Light source coupler, illuminant device, patterned conductor, and method for manufacturing light source coupler

ABSTRACT

To provide a light source assembly that does not use a printed circuit board and can be manufactured at a low cost even when produced in small quantities, a light source assembly according to the present invention comprises a plurality of light sources and a connective conductor structure extending in a direction of arrangement of the light sources to join the light sources, wherein the connective conductor structure is formed by cutting off parts of a substantially plate-like patterned conductor as required, the patterned conductor being provided with a prescribed pattern. Thus, by changing the parts to be cut off in the patterned conductor, it is possible to manufacture light source assemblies having various light source connection patterns in a single manufacturing line, allowing efficient and low cost manufacture of the light source assemblies to be achieved even when the light sources are manufactured in small quantities.

TECHNICAL FIELD

The present invention relates to a light source assembly formed byelectrically connecting a plurality of light sources, a light emittingapparatus using the light source assembly, a patterned conductor forforming the light source assembly and a method for forming the lightsource assembly.

BACKGROUND OF THE INVENTION

Light emitting apparatuses having a plurality of light sources arrangedon a surface of a holder are used not only in general illumination butalso in various usages such as advertisement, decoration, signaling andthe like. In order to form such a light emitting apparatus, it may beconceived to use bullet-type LED light sources having lead wires and aprinted circuit board formed with through-holes into which the leadwires of the light sources are inserted and a conductor pattern fortransmitting electric power to the light sources, and to connect thelead wires of the light sources to the conductor pattern of the printedcircuit board by means of flow soldering.

Such a structure that utilizes a printed circuit board as a holder ofthe light sources can bring about an economic benefit when manufacturedon a large scale. However, in a case that a variety of light emittingapparatuses having different light source arrangements and connectionpatterns are produced in small quantities, it can rather lead to ahigher manufacturing cost. Further, contact with the molten solder inthe soldering process will expose the printed circuit board to a hightemperature, and this is undesirable to LEDs, which can be easilydamaged by heat. Further, the solder typically contains lead, and thusthe use thereof necessitates environmental measures. It may be conceivedto use a leadless solder, but the leadless solder is higher in price aswell as in melting temperature, which can worsen the detrimental effectsof heat against the LEDs. Furthermore, the printed circuit board makesit difficult to arrange the light sources on a curved surface. In thecase that flexible conductive wires are used to connect light sources,the process of connection may become cumbersome and this can lead to ahigher manufacturing cost. The printed circuit board also has a problemthat recycling thereof is quite difficult because the printed circuitboard has unitary wirings and support board.

To provide a light emitting module without a printed circuit board andsolder, Japanese Patent Application Laid-Open No. 7-106634 has disclosedto connect a plurality of LEDs between an anode bus bar and cathode busbar by means of mechanical engagement. Further, Japanese PatentApplication Laid-Open No. 8-316531 has disclosed a light emitting modulecomprising a plurality of bus bar pairs, a plurality of LEDs attachedbetween each bus bar pair, and flexible joints for electrically andmechanically connecting adjacent bus bar pairs, so that athree-dimensional configuration of the light emitting module ispossible. In these laid-open publications, however, there is nodisclosure regarding a light source assembly that can allow easyselection of various light source connection patterns and yet can bemanufactured with high production efficiency, nor is there a disclosureregarding a manufacturing method therefor.

BRIEF SUMMARY OF THE INVENTION

The present invention was made to solve the above prior art problems,and a primary object of the present invention is to provide a lightsource assembly comprising a plurality of light sources that can bemanufactured with high efficiency and at low cost without using aprinted circuit board, and to provide a manufacturing method therefor.

A second object of the present invention is to provide a light sourceassembly that can eliminate or considerably reduce an amount of solderused therein, and to provide a manufacturing method therefor.

A third object of the present invention is to provide a light sourceassembly that can easily achieve various arrangements of light sources,and to provide a manufacturing method therefor.

A fourth object of the present invention is to provide a light sourceassembly as mentioned above and utilizing a chip-type LED as a lightsource, and to provide a manufacturing method therefor.

A fifth object of the present invention is to provide a light emittingapparatus using a light source assembly as mentioned above.

A sixth object of the present invention is to provide a tape-shapedconductor for use in forming a light source assembly as mentioned above.

In order to accomplish such objects, according to one aspect of thepresent invention, there is provided a light source assembly comprising:a plurality of electrically connected light sources; and a connectiveconductor structure extending in a direction of arrangement of the lightsources to join the light sources, wherein the connective conductorstructure is formed by cutting off parts of a substantially plate-likepatterned conductor as required, the patterned conductor being providedwith a prescribed pattern. The patterned conductor can be formed bypress working a conductive plate material. According to such astructure, because the light source assembly can be manufactured withoutusing a printed circuit board, the solder used for attachment with theprinted circuit board is no longer necessary. This can eliminate concernabout environmental problems as well as a possibility that LEDs may bedamaged due to heat generated in use of solder. Further, by varying theparts to be cut off in the patterned conductor, it is possible to formconnective conductor structures having various light source connectionpatters by using the same patterned conductor in a single manufacturingline, and thus efficient and low cost manufacture is possible even whenlight source assemblies having various light source connection patternsare manufactured in small quantities. The light source assembly can bemade deformable into a desired shape by providing an appropriateflexibility to the patterned conductor when forming it from a conductiveplate material, so that various arrangement of light sources can beattained easily. The nonuse of the printed circuit board also allowseasy recycling of the light source assembly when it is no longer used.Further, if the patterned conductor is of a longitudinal tape-likeshape, it is possible to conduct various processes such as attachment ofthe light sources and press working of the patterned conductor whiletransporting the patterned conductor in a manufacturing line, to therebyallow continuous fabrication of the light source assembly. It can bealso easily attained to provide a light source assembly of a desiredlength by cutting the patterned conductor at an appropriate length.

According to one embodiment of the present invention, the plurality oflight sources comprise a chip-type LED, and a socket for receiving thechip-type LED is attached to the connective conductor structure byinsert molding. Typically, the socket comprises a bottom wall and a sidewall defining a cavity having an upper opening, and the chip-type LED isreceived in the cavity. In this way, even when a chip-type LED withoutlead wires is used as a light source, it is possible to easily attachthe chip-type LED to the connective conductor structure to obtain alight source assembly.

Preferably, the bottom wall of the socket is formed with a hole so thatthe LED received in the socket can be pushed through the hole andthereby removed from the socket. This can allow quick replacement of amalfunctioning LED with a normal one. It will be also preferable in viewof quick installment of the LED into the socket if a portion of theconnective conductor structure is exposed in the cavity of the socket soas to contact electric terminals of the chip-type LED received in thesocket. Further preferably, the portion of the connective conductorstructure exposed in the cavity of the socket has projections forcontacting the electric terminals of the LED. This can ensure electricconnection between the LED and the connective conductor. If a portion ofthe connective conductor structure is bent so as to engage with the LEDreceived in the socket to thereby prevent removal of the LED from thesocket, inadvertent removal of the LED can be preferably prevented evenwhen the light source assembly is placed upside-down.

In another embodiment of the present invention, the chip-type LED is ofa side-view type having a light emitting portion on its side, and atleast part of the side wall of the socket has an opening for allowinglight from the light emitting portion of the LED to pass through theside wall. Thus, it is possible to use side-view LEDs

According to yet another embodiment of the present invention, theplurality of light sources comprise a light source having a lead wire,and the connective conductor structure has a hole corresponding to thelead wire of the light source. Preferably, a portion of the connectiveconductor structure defining the hole comprises projections extendinginto the hole. Typically, the lead wire of the light source is insertedinto the hole of the connective conductor structure, wherebyelectrical/mechanical connection between the light source and theconnective conductor structure is achieved. Further, it will befavorable in view of preventing inadvertent removal of the light sourcesif the lead wire is cramped by a portion of the connective conductorstructure near the hole of the connective conductor structure to achieveattachment of the light source to the connective conductor structure.Instead of directly inserting the lead wire of the light source into thehole of the connective conductor structure, it may be possible that apin portion of a socket pin is inserted into the hole of the connectiveconductor structure, and the lead wire is inserted into a socket portionof the socket pin.

According to yet another embodiment of the present invention, each ofthe plurality of light sources has a pair of lead wires extendingsubstantially in parallel to each other, and the plurality of lightsources are arranged in a direction substantially perpendicular to thelead wires, wherein the connective conductor structure is disposed suchthat its principal surface extends substantially along the lead wires,and attached to the lead wires to join the light sources. In such acase, it is preferable that the patterned conductor is of a longitudinaltape-like shape, and comprises a plurality of connection parts for thelead wires of the light sources, the connection parts being arrangedcorresponding to an arrangement of the light sources held by a radialtaping. This can allow the attachment of the light sources to thepatterned conductor to be carried out in a state where the plurality oflight sources are unitarily held by the radial taping, and thus improvethe work efficiency. After attaching the light sources to the patternedconductor, the lead wires are cut at a predetermined position and partsof the patterned conductor are cut off as required to form a connectivestructure, to thereby obtain a light source assembly. Further, it willbe preferred if a cross-sectional shape of the connective conductorstructure taken along a plane perpendicular to the longitudinaldirection is bent. This can prevent undesirable contact between theconnective conductor structure and the lead wires and thus avertinadvertent short-circuit even in a simple configuration that theconnective conductor structure is exposed without being coated withinsulating material. The exposed connective conductor structure withoutinsulating coating provides improved heat dissipation and thus canfavorably cope with high density arrangement of the light sources.Further, because the longitudinal flexion is limited, the light sourceassembly can be easily handled when attaching it to the holder.

Preferably, the patterned conductor is of a longitudinal tape-likeshape, and comprises: a plurality of light source attachment portionsarranged in a longitudinal direction for electrical connection with thelight sources; an interconnection path for connecting the light sourceattachment portions in the longitudinal direction; at least one trunkpath widthwise spaced from the interconnection path and the light sourceattachment portions and extending in the longitudinal direction; and aplurality of branch paths widthwise connecting the trunk path to theinterconnection path. Thus, by cutting off prescribed portion of thebranch paths, interconnection path or trunk path, a connective conductorstructure for connecting the light sources in any of various connectionpatterns can be formed. In the light source assembly having theconnective conductor structure thus formed, the trunk path can be usedto connect the light sources to a power supply, favorably eliminatingthe need for additional wirings. In a case where parts of the trunk pathare cut off so that the connective conductor structure connects thelight sources in series, remaining parts of the trunk path can beconnected to the light source attachment portions via the branch pathsso that they can serve as heat dissipating portions for dissipating heatgenerated from the light sources, to thereby contribute preventingexcessive increase in the temperature around the light sources.

In the light source assembly manufactured by using such a patternedconductor, it is possible that a resistor is connected between at leastone pair of adjoining light sources, and the interconnection path is cutat a position between the pair of adjoining light sources. Thus, aresistor for preventing an excessive voltage from being applied to alight source, for example, can be connected to the light source.

Further preferably, the light source assembly may comprise a jointmember extending in a widthwise direction of the connective conductorstructure to hold the interconnection path and the trunk path in a unit.In this way, when pats of patterned conductor are cut off as required toform the connective conductor structure, it is possible to prevent theparts of the resulting connective conductor structure from beingseparated apart. Further, the joint member improves the mechanicalstrength of the connective conductor structure. Such a joint member canbe preferably formed by insert molding. In the case that the jointmember is formed by insert molding, it is favorable that the trunk pathis formed with a widthwise recess of through-hole, and the joint memberextends through the widthwise recess or through-hole because this canfirmly engage the joint member to the trunk path. Further preferably,the joint member is formed with a hole at a position aligned with theinterconnection path such that the hole exposes the interconnectionpath, thereby allowing a part of the interconnection path exposed by thehole to be cut off. In this way, it is possible to form a connectiveconductor structure having a desired light source connection pattern bycutting the interconnection path after forming the joint member. Thepart of the interconnection path exposed by the hole of the joint membermay have a smaller width than the other part of the interconnection pathso that it can be cut off easily. The joint member may comprise one or aplurality of insulating sheets. A plurality of insulating sheets mayextend widthwise at predetermined positions or alternatively, a singleinsulating sheet may extend substantially a whole length of theconnective conductor structure. By using such insulating sheets, theresultant light source assembly can be smaller (or thinner) comparedwith that manufactured using the joint member formed by insert molding.If the insulating sheet is attached to a light source attachment surfaceof the connective conductor structure, it is prevented that a partapplied with the power supply voltage is exposed on the light sourceattachment surface where a personnel may touch with a relatively highpossibility, and thus the safety is improved. Further, since theinsulating sheet can reflect the light from the light sources,illumination efficiency can be increased.

When the light source assembly does not have insert molded joint membersor when such joint members are removed after the light sources areattached to the connective conductor structure, it is possible that thebranch paths connecting the trunk path to the interconnection path arebent such that a principal surface of the trunk path is substantiallyperpendicular to a principal surface of the interconnection path. Inthis way, by inserting the trunk path into an aligned recess or holeformed in the holder, the light source assembly can be easily attachedto the holder.

In place of the joint member or in addition to the joint member, it ispossible to provide a socket for receiving a chip-type LED, such thatthe socket extends in a widthwise direction of the connective conductorstructure to hold the interconnection path and the trunk path in a unit.

In the case where the plurality of light sources comprise a chip-typeLED, a light source attachment portion associated with the chip-type LEDmay have terminal connection parts corresponding to terminals of thechip-type LED, and at least one of the terminal connection parts mayhave an extension which is bent to form a wall for positioning orholding the chip-type LED. Preferably the terminal connection parts ofthe light source attachment portion associated with the chip-type LEDhave a pair of extensions opposing to each other. This can eliminate theneed for a socket formed by insert molding or the like.

It is not necessary to attach a light source to every light sourceattachment portion, and it is possible that at least one of the lightsource attachment portions is not attached with a light source. This canflexibly vary the interval between the light sources. When the lightsources are connected in series or in series-parallel connections, forexample, such non-attachment of the light source can be achieved bycoupling the terminal connection parts in each light source attachmentportion when the patterned conductor is formed (primary processing), andin the secondary processing of the patterned conductor, separating theterminal connection parts only in the light source attachment portionswhere the light sources are actually attached.

When at least one of the plurality of light sources consists of a lightsource having a pair of terminals, the pair of terminals of the lightsource may be arranged in a widthwise direction of the light sourceassembly. In this way, when the light source assembly is flexed in thelongitudinal direction, there is no force produced for urging theterminals of the light sources away from the connective conductorstructure, and thus undesirable removal of the light sources from theconnective conductor structure can be prevented. This can be preferablyrealized by that the light source attachment portion to which the lightsource having a pair of terminals is attached has a pair of terminalconnection parts corresponding to the pair of terminals, and the pair ofterminal connection parts are arranged in the widthwise direction of thepatterned conductor.

When each of the light sources has a pair of terminals, it is preferablethat the patterned conductor is provided with a pattern that can becommonly used in connecting the light sources in series, parallel orseries-parallel connection. This can allow a light source assemblyhaving light sources connected in any of series, parallel orseries-parallel connections to be formed from the same patternedconductor, and thus can achieve increase in the production efficiencyand decrease in the manufacturing cost. According to a preferredembodiment of the present invention, the patterned conductor is of alongitudinal tape-like shape, and comprises: a plurality of light sourceattachment portions arranged in a longitudinal direction for electricalconnection with the light sources; an interconnection path forconnecting the light source attachment portions in the longitudinaldirection; a pair of trunk paths disposed on either side of thepatterned conductor so as to interpose the interconnection path and thelight source attachment portions therebetween and extending in thelongitudinal direction; and a plurality of branch paths widthwiseconnecting the trunk paths to the interconnection path. In such astructure, it is possible to cut off a portion of the branch paths,interconnection path or trunk paths as required to form connectiveconductor structures having various light source connection patternsfrom the common patterned conductor in a single manufacturing lineeasily and efficiently, and thus the manufacturing cost can be reducedeven when the light source assemblies are manufactured in smallquantities. Preferably, each of the light source attachment portions hasa pair of terminal connection parts corresponding to the pair ofterminals of the light sources, and the interconnection path comprises aplurality of connection paths each connecting the terminal connectionparts contained in adjoining light source attachment portions.

When the plurality of light sources comprise a three-pole LED lamphaving two different color LED chips and three terminals, it will bepreferable if the patterned conductor is of a longitudinal tape-likeshape, and comprises: a plurality of light source attachment portionsarranged in a longitudinal direction for electrical connection with thelight sources; an interconnection path for connecting the light sourceattachment portions in the longitudinal direction; a pair of trunk pathsdisposed on either side of the patterned conductor so as to interposethe interconnection path and the light source attachment portionstherebetween and extending in the longitudinal direction; and aplurality of branch paths widthwise connecting the trunk paths to theinterconnection path, wherein each of the light source attachmentportions has three widthwise arranged terminal connection partscorresponding to the three terminals of the three-pole LED lamp, and theinterconnection path comprises a plurality of connection paths eachconnecting the widthwise aligned terminal connection parts contained inadjoining light source attachment portions. In this way, a light sourceassembly using three-pole LED lamps as light sources can be realized,which, when connected to an appropriate power supply and switches, canvariously change the color of the illuminated light.

When the plurality of light sources comprise a four-pole LED lamp havingfirst and second LED chips of different colors and four terminals, andtwo of the four terminals are connected to the first LED chip while theremaining two are connected to the second LED chip, it will bepreferable if the patterned conductor is of a longitudinal tape-likeshape, and comprises: a plurality of light source attachment portionsarranged in a longitudinal direction for electrical connection with thelight sources; an interconnection path for connecting the light sourceattachment portions in the longitudinal direction; a pair of trunk pathsdisposed on either side of the patterned conductor so as to interposethe interconnection path and the light source attachment portionstherebetween and extending in the longitudinal direction; and aplurality of branch paths widthwise connecting the trunk paths to theinterconnection path, wherein each of the light source attachmentportions has four terminal connection parts corresponding to the fourterminals of the four-pole LED chip, two of the four terminal connectionparts corresponding to the terminals connected to the first LED chipbeing aligned in the longitudinal direction of the patterned conductorwhile two of the four terminal connection parts corresponding to theterminals connected to the second LED chip being aligned in thelongitudinal direction of the patterned conductor and spaced from theother two terminal connection parts in a widthwise direction of thepatterned conductor, wherein the interconnection path comprises aplurality of connection paths each connecting the widthwise alignedconnection parts contained in adjoining light source attachmentportions, and longitudinally aligned ones of the plurality of connectionpaths are connected by widthwise extending branch paths, and wherein thepatterned conductor further comprises a third trunk path disposed at awidthwise outer side of one of the first and second trunk paths andextending in the longitudinal direction, and branch paths for widthwiseconnecting the third trunk path to the one of the first and second trunkpaths. In this way, a light source assembly using four-pole LED lamps aslight sources can be realized, which, when connected with an appropriatepower supply and switches, can variously change the color of theilluminated light.

Preferably, the patterned conductor is essentially made of aluminum. Itwill be preferable if the light sources are attached to the connectiveconductor structure by laser welding because the attachment can behighly reliable. Further, a resistor for forming a prescribed circuittogether with the light sources may be connected to the connectiveconductor structure by laser welding. Typically, the light sourceattached to the connective conductor structure by laser welding consistsof a chip-type LED (or surface-mount type LED), and the resistorconsists of a chip-type resistor (or surface-mount type resistor), butthey may not be limited to the chip-type devices, and the laser weldingmay be applied to the light source having lead wires as terminals forelectric connection.

It is also possible that at least one of the plurality of light sourcesconsists of a light emitting element assembly comprising a plurality oflight emitting elements. Further, it will be convenient if the patternedconductor comprises projections for defining attachment positions of thelight sources.

In yet another preferred embodiment of a light source assembly accordingto the present invention, the patterned conductor comprises a pair oftrunk paths extending substantially in parallel in a longitudinaldirection and a plurality of branch paths connecting the pair of trunkpaths to each other, the light sources are connected between the pair oftrunk paths, and the cut-off parts of the patterned conductor includethe branch paths. This embodiment is particularly suitable for embodyinga light source assembly in which the plurality of light sources areconnected in parallel between the pair of trunk paths. Since the pair oftrunk paths are connected to each other by the branch paths, thepatterned conductor can be handled quite easily, which can improve theproduction efficiency. If a gap between the pair of trunk paths is notstraight (for example, bent in a rectangular wave), the attachmentpositions of the light sources (LEDs) connected between the pair oftrunk paths can be adjusted not only in the longitudinal direction butalso in the widthwise direction. Thus, in a case that the light sourceassemblies are used in forming automobile lamps, for example, it ispossible to cope with a situation where different LED arrangementpatterns are required for different vehicle types. This can lead toparts sharing and bring about significant economic benefits.

When each of the light sources consists of an LED having a plate-shapedcathode terminal and anode terminal, it is preferred that a portion ofthe patterned conductor to which the cathode terminal of each LED isattached has a larger area than a portion of the same to which the anodeof each LED is attached. This is because that in such an LED, an LEDchip encapsulated within a package is usually mounted on the cathodeterminal and connected to the anode terminal via thin lead wire, andthus the heat generated from the LED chip is mainly discharged via thecathode terminal. When a portion of the patterned conductor to which thecathode terminal of each LED is attached has a larger area, the heatdischarged via the cathode terminals can be efficiently dissipated. Inthe case where the patterned conductor comprises a pair of trunk pathsextending substantially in parallel in a longitudinal direction, and theLEDs are connected between the pair of trunk paths, the trunk path towhich the cathode terminals of the LEDs are attached may preferably havea larger width than the trunk path to which the anode terminals of theLEDs are attached.

According to another aspect of the present invention, there is provideda light emitting apparatus comprising a light source assembly having aplurality of electrically connected light sources and a holder forholding the light source assembly, wherein the light source assemblycomprises a connective conductor structure extending in a direction ofarrangement of the light sources to join the light sources, theconnective conductor structure being formed by cutting off parts of asubstantially plate-like patterned conductor as required, the patternedconductor being provided with a prescribed pattern, wherein thepatterned conductor is of a longitudinal tape-like shape, and comprises:a plurality of light source attachment portions arranged in alongitudinal direction for electrical connection with the light sources;an interconnection path for connecting the light source attachmentportions in the longitudinal direction; a pair of trunk paths disposedon either side of the patterned conductor so as to interpose theinterconnection path and the light source attachment portionstherebetween and extending in the longitudinal direction; and aplurality of branch paths widthwise connecting the trunk path to theinterconnection path, and wherein the branch paths connecting the trunkpaths to the interconnection path are bent such that a principal surfaceof each trunk path is substantially perpendicular to a principal surfaceof the interconnection path, and the trunk paths are inserted intocorresponding holes or recesses provided to the holder to achieveattachment of the light source assembly to the holder. In this lightemitting apparatus, the light source assembly can be attached to theholder by just inserting the trunk paths into the recesses or holes ofthe holder, and thus the efficiency of process of attaching can beimproved.

According to another embodiment, there is provided a light emittingapparatus comprising a light source assembly having a plurality ofelectrically connected light sources each having lead wires and a holderfor holding the light source assembly, the light sources being arrangedin a direction substantially perpendicular to the lead wires, whereinthe light source assembly comprises a connective conductor structureextending in the direction of arrangement of the light sources to jointhe light sources, and wherein one or both of the lead wires and theconnective conductor structure protrude toward the holder and areinserted into holes or recesses provided to the holder to achieveattachment of the light source assembly to the holder. In such a lightemitting apparatus, it is only necessary for the holder to be formedwith holes or recesses, and thus no complicated processes are needed.This makes it possible to easily manufacture various light emittingapparatuses having different light source arrangements, and thus canreduce the cost when various light emitting apparatuses are manufacturedin small quantities. Further, the light emitting apparatus can besecurely attached to the holder with a simple structure. Also, since theconnective conductor structure is disposed between the holder and thelight source bodies, the light source bodies can be held spaced apartfrom a surface of the holder, which improves heat dissipation.

According to yet another aspect of the present invention, there isprovided a tape-shaped patterned conductor having a prescribed patternand used for forming a light source assembly by electrically connectinga plurality of light sources, comprising: a plurality of light sourceattachment portions arranged in a longitudinal direction for connectionwith the light sources; an interconnection path connecting the lightsource attachment portions in the longitudinal direction; at least onetrunk path widthwise spaced from the interconnection path and the lightsource attachment portions and extending in the longitudinal direction;and a plurality of branch paths widthwise connecting the trunk path tothe interconnection path. By using such a tape-shaped patternedconductor, it is possible to manufacture a light source assembliesefficiently without using a printed circuit board. Further, by cuttingoff a portion of the branch paths and/or interconnection path asrequired, light source assemblies having light sources connected invarious connection patterns can be formed easily.

The cutting (secondary processing) of the patterned conductor can beachieved efficiently and at low cost if it is done by press workingusing a progressive press machine. Therefore, it is preferable that thetrunk path is formed with a plurality of holes (pilot holes) arranged inthe longitudinal direction at a predetermined interval for use intransportation or positioning of the patterned conductor in aprogressive press machine. When each of the light sources has a pair ofterminals for electrical connection, each of the light source attachmentportions should have a pair of terminal connection parts for connectionwith the pair of terminals of a corresponding light source. In such acase, the interconnection path may comprise a plurality of connectionpaths each connecting the terminal connection parts contained inadjoining light source attachment portions. It is also possible that atleast one of the connection paths and/or trunk path is formed with ahole for inserting a lead wire of a resistor having lead wires. If thepair of terminal connection parts in each light source attachmentportion are spaced from each other, the number of parts need to be cutoff in the secondary processing of the patterned conductor can bereduced while if the pair of terminal connection parts in each lightsource attachment portion are connected to each other, the partconnecting the pair of terminal connection parts can be selectively cutoff as needed, and thus the flexibility is improved. Further, a resistorattachment portion may be provided between at least one adjoining pairof light source attachment portions. It may be also possible that atleast one of the branch paths may be replaced with a resistor. In thisway, a resistor can be easily incorporated in the circuit. The trunkpath may have a widthwise convexly curved portion. By bending theconvexly curved portion at its root, it can be used in attachment to theholder. When a progressive press machine is used in attaching aplurality of light sources held by the radial taping to an unwoundportion of the tape-shaped patterned conductor wound in a coil, thetrunk path of the patterned conductor may interfere with main bodies ofthe light-sources. In such a case, however, if the trunk path is formedwith convexly curved portions, the interference between the trunk pathof the tape-shaped patterned conductor and the main bodies of the lightsources can be prevented by bending the convexly curved portions in theunwound portion of the tape-shaped patterned conductor.

Further preferably, a pair of trunk paths may be disposed on either sideof the patterned conductor so as to interpose the interconnection pathand the light source attachment portions therebetween. In such aconfiguration, it is possible to form a light source assembly connectingthe light sources in any of serial-parallel, parallel or seriesconnections by cutting off a prescribed portion of the branch pathand/or interconnection path. Thus, light source assemblies havingvarious connection patters can be manufactured from the same patternedconductor in a single manufacturing line, advantageously improving theproduction efficiency and reducing the manufacturing cost.

According to another embodiment of the present invention, there isprovided a tape-shaped patterned conductor having a prescribed patternand used for forming a light source assembly by electrically connectinga plurality of light sources, wherein parts of the patterned conductorare to be cut off by a progressive press machine as required to form aconnective conductor structure for connecting the light sources, andwherein the patterned conductor is formed with a plurality of holesarranged in a longitudinal direction at a predetermined interval for usein transportation or positioning of the patterned conductor in theprogressive press machine. According to still another embodiment, thereis provided a tape-shaped patterned conductor having a prescribedpattern and used for forming a light source assembly by electricallyconnecting a plurality of light sources each having lead wires, thelight sources being arranged in a direction substantially perpendicularto the lead wires, the patterned conductor comprising: a plurality ofconnection parts arranged in a longitudinal direction for connectionwith the lead wires of the plurality of light sources; and aninterconnection path for connecting the connection parts in thelongitudinal direction, wherein the interconnection path is formed withpilot holes for engagement with pilot pins of a progressive pressmachine. Thus, by providing the patterned conductor with a plurality ofholes used for transportation or positioning of the patterned conductorin the progressive press machine, the handling of the patternedconductor by the progressive press machine can be facilitated and theproduction efficiency of the light source assembly using the patternedconductor can be improved.

According to still another aspect of the present invention, there isprovided a manufacturing method of a light source assembly comprising aplurality of light sources and a connective conductor structure forelectrically connecting the plurality of light sources, the methodcomprising the steps of: forming a substantially plate-like patternedconductor having a prescribed pattern; attaching the patterned conductorto the light sources; and cutting off parts of the patterned conductoras required to form the connective conductor structure. In this way, bychanging the parts to be cut out in the patterned conductor, it ispossible to form a light source assembly comprising a connectiveconductor structure having various light source connection patterns.Also this manufacturing method can eliminate use of solder which isusually used in a printed circuit board or for connection with theprinted circuit board.

Preferably, the step of forming the tape-shaped patterned conductorcomprises a step of press working a conductive plate material. It willbe further preferable in view of work efficiency if the step of cuttingoff parts of the patterned conductor and/or attaching the patternedconductor to the light sources is carried out by a progressive pressmachine. If the manufacturing method further comprises a step ofattaching a joint member to the patterned conductor so as to hold partsof the connective conductor structure made from the patterned conductor,and the step of cutting off parts of the patterned conductor is carriedout after the step of attaching the joint member, it is possible toprevent the parts of the connective conductor structure from beingseparated apart. In such a case, it is preferable that the joint memberis formed with at least one hole to expose a part of the patternedconductor to be cut off, whereby allowing the part of the patternedconductor exposed by the hole can be cut as required. If the lightsources comprise a chip-type LED, and the present method comprises astep of attaching a socket to the patterned conductor for receiving thechip-type LED, the step of cutting off parts of the patterned conductorcan be carried out after the step of attaching the socket.

If the light sources comprise a light source having lead wires, the stepof attaching the patterned conductor to the light sources may comprise astep of inserting the lead wires of the light source into correspondingholes provided to the connective conductor structure.

It may be also possible that the step of cutting off parts of thepatterned conductor is carried out after the step of attaching thepatterned conductor to the light sources. This can prevent the parts ofthe connective conductor structure, which is formed by cutting off partsof the patterned conductor as required, from being separated apartwithout using the joint member. Further, if each of the light sourceshas a pair of lead wires for electric connection, the step of attachingmay preferably comprise step of cramping the lead wires with prescribedportions of the patterned conductor, to thereby eliminate use of solder.The engagement by cramping is also preferred for the reason that it issuitable to be carried out by progressive press working. The method mayfurther comprise the step of bending the patterned conductor along abending line extending in the longitudinal direction, so as to preventundesirable contact between the patterned conductor (or the connectiveconductor structure made therefrom) and the lead wires of the lightsources.

According to a further embodiment of the present invention, there isprovided a manufacturing method of a light source assembly having aplurality of light sources each having lead wires, wherein the lightsources are arranged in a direction substantially perpendicular to thelead wires, comprising the steps of: supplying the plurality of lightsources arranged in the direction perpendicular to the lead wires andheld by a carrier tape for radial taping; and electrically connectingthe light sources in a state that the light sources are held by thecarrier tape to thereby continuously obtain the light sources. In thismethod, the connecting of the light sources is conducted while the lightsources are held unitarily, and thus the workability in the manufactureof the light source assembly can be improved.

According to another aspect of the present invention, there is provideda light emitting apparatus comprising: a light source assembly having aplurality of electrically connected light sources, a light transmissivetubular member for accommodating the light source assembly therein; anda pair of cap members attached to either end of the tubular member,wherein the light source assembly comprises a connective conductorstructure for connecting the light sources, and the connective conductorstructure is formed by cutting off parts of a substantially plate-likepatterned conductor as required, the patterned conductor being providedwith a prescribed pattern. In such a light emitting apparatus, theconnective conductor structure can be significantly thicker (0.1-0.3 mm)than a circuit-forming copper film (typically 35 μm) of a printedcircuit board to thereby improve heat conducting property. Thus, it ispossible to transfer heat generated from the light sources or otherelements (resistors) quickly and prevent excessive increase intemperature around the light sources or other elements to therebyprevent damage to them.

Preferably, the patterned conductor is of a longitudinal tape-likeshape, and comprises: a plurality of light source attachment portionsarranged in a longitudinal direction for electrical connection with thelight sources; an interconnection path for connecting the light sourceattachment portions in the longitudinal direction; at least one trunkpath widthwise spaced from the interconnection path and the light sourceattachment portions and extending in the longitudinal direction; and aplurality of branch paths widthwise connecting the trunk path to theinterconnection path. When a conductive pin for connection with anoutside circuit is held in at least one of the pair of cap members, itwill be preferable that the trunk path is connected to the conductivepin because it can eliminate the need for additional wirings and thusimprove work efficiency.

According to yet another aspect of the present invention, there isprovided a light emitting apparatus comprising a light source assemblyhaving a plurality of electrically connected light sources, wherein thelight source assembly comprises a connective conductor structure forconnecting the light sources, and the connective conductor structure isformed by cutting off parts of a substantially plate-like patternedconductor as required, the patterned conductor being provided with aprescribed pattern, and wherein the light emitting apparatus comprises:a housing for accommodating the light source assembly therein; and aheat transmission member contacting the connective conductor structureof the light source assembly and an inner surface of the housing totransmit heat therebetween. In such a configuration, the heat generatedfrom the light sources or the like is transmitted from the connectiveconductor structure to the housing, and then dissipated to outside fromthe housing, and therefore, it is possible to suppress increase in thetemperature within the housing, and thus prevent damage to the lightsources or other elements or performance decrease of the same. In otherwords, the use of heat transmission member can make the housing work asa heat sink.

The heat transmission member can also serve as a support member forsupporting the light source assembly in the housing, and this can makean additional support member unnecessary. Preferably, the heattransmission member is elastic, and pressed against the inner surface ofthe housing because this can improve the heat transmission to thehousing as well as securely support the light source assembly withoutundesirable play. The housing is preferably made of a material having afavorable heat transmission property such as glass. If the patternedconductor is of a longitudinal tape-like shape, and comprises: aplurality of light source attachment portions arranged in a longitudinaldirection for electrical connection with the light sources; aninterconnection path for connecting the light source attachment portionsin the longitudinal direction; at least one trunk path widthwise spacedfrom the interconnection path and the light source attachment portionsand extending in the longitudinal direction; and a plurality of branchpaths widthwise connecting the trunk path to the interconnection path,the heat transmission member can be connected to the trunk path.

According to another aspect of the present invention, there is provideda light emitting apparatus comprising a light source assembly having aplurality of electrically connected light sources and a holder forholding the light source assembly, wherein the light source assemblycomprises a connective conductor structure extending in a direction ofarrangement of the light sources to join the light sources, theconnective conductor structure being formed by cutting off parts of asubstantially plate-like patterned conductor as required, the patternedconductor being provided with a prescribed pattern, wherein thepatterned conductor is of a longitudinal tape-like shape, and comprises:a plurality of light source attachment portions arranged in alongitudinal direction for electrical connection with the light sources;an interconnection path for connecting the light source attachmentportions in the longitudinal direction; a pair of trunk paths disposedon either side of the patterned conductor so as to interpose theinterconnection path and the light source attachment portionstherebetween and extending in the longitudinal direction; and aplurality of branch paths widthwise connecting the trunk path to theinterconnection path, and wherein at least one surface of the holder isformed with a channel having opposing side walls in which longitudinallyextending guide grooves are formed corresponding to the pair of trunkpaths so that the light source assembly is attached to the holder bysliding the pair of the trunk paths into the guide grooves. In such alight emitting apparatus, the attachment of the light source assembly tothe holder can be achieved readily.

If both surfaces of the holder are formed with a channel, and opposingside walls of each channel are formed with longitudinally extendingguide grooves corresponding to the pair of trunk paths, it is possiblethat each surface of the holder is attached with the corresponding lightsource assembly with the pair of trunk paths slid into the guidegrooves, so that the light can be emitted on both sides of the holder.

According to yet another aspect of the present invention, there isprovided a tape-shaped patterned conductor having a prescribed patternand used for forming a light source assembly by electrically connectinga plurality of light sources, comprising: more than two trunk pathsextending in a longitudinal direction and mutually spaced apart in awidthwise direction; a plurality of light source attachment portions forelectrical connection with the light sources, the light sourceattachment portions being arranged in the longitudinal direction betweenadjoining trunk paths; interconnecting paths for connecting theplurality of light source attachment portions in the longitudinaldirection; and a plurality of branch paths for widthwise connecting eachof the interconnection paths to the trunk paths interposing theinterconnection path therebetween. By using such a patterned conductor,it is possible to easily form a light source assembly having lightsources arranged in a plurality of lines, and thus improve productionefficiency.

According to still another aspect of the present invention, there isprovided a light emitting apparatus comprising a plurality of lightsource assemblies each having a plurality of electrically connectedlight sources, wherein each of the light source assemblies comprises aconnective conductor structure extending in a direction of arrangementof the light sources to join the light sources, the connective conductorstructure being formed by cutting off parts of a substantiallyplate-like patterned conductor as required, the patterned conductorbeing provided with a prescribed pattern, and wherein the plurality oflight sources are arranged in the widthwise direction, and adjoininglight sources are connected to each other so that the plurality of lightsource assemblies are connected in series. Thus, it is possible to uselight source assemblies to constitute a light emitting apparatus inwhich light sources are connected in a matrix pattern. Such a lightemitting apparatus is suitable for a traffic light, for example, becauseeven if a single light source breaks down and stops current conduction,its influence on the other light sources is small.

When each of the light sources consists of an LED and each LED isconnected in series with a resistor, if a single LED suffers ashort-circuiting malfunction, the voltage can be maintained by theresistor connected in series to the malfunctioning LED, and therefore,the LEDs connected in parallel with the malfunctioning LED can continueemitting light so that a significant decrease in the amount of emittedlight can be avoided.

According to another aspect of the present invention, there is provideda light source assembly comprising a plurality of electrically connectedlight sources, wherein the light source assembly comprises a connectiveconductor structure extending in a direction of arrangement of the lightsources to join the light sources, the connective conductor structurebeing formed by cutting off parts of a substantially plate-likepatterned conductor as required, the patterned conductor being providedwith a prescribed pattern, wherein the patterned conductor is of alongitudinal tape-like shape, and comprises: a plurality of light sourceattachment portions arranged in a longitudinal direction for electricalconnection with the light sources; an interconnection path forconnecting the light source attachment portions in the longitudinaldirection; a pair of trunk paths disposed on either side of thepatterned conductor so as to interpose the interconnection path and thelight source attachment portions therebetween and extending in thelongitudinal direction; and a plurality of branch paths widthwiseconnecting the trunk path to the interconnection path, and wherein partsof the interconnection path are cut off to form a plurality of lightsource parallel connections each comprising a plurality of light sourcesconnected in parallel between the pair of trunk paths, and further,parts of the trunk paths are cut such that the light source parallelconnections are connected in series. This can provide a light sourceassembly comprising light sources spatially arranged in a line andelectrically connected in a matrix pattern.

When each of the light sources consists of an LED, the above lightsource assembly can be easily embodied if orientations of the LEDscontained in adjoining light source parallel connections are opposite toeach other so that cathodes of the LEDs contained in an electricallyupstream one of the adjoining light source parallel connections areconnected to anodes of the LEDs contained in a downstream one via one ofthe pair of trunk paths, and if the pair of trunk paths are cut suchthat anodes of the LEDs contained in the upstream one of the adjoiningparallel connections are separated from cathodes of the LEDs containedin the downstream one and that ends of each LED are not short-circuited.

Alternatively, the above light source assembly can be embodied byconnecting portions of the pair of trunk paths to each other via thebranch paths and the light source attachment portions such that cathodesof the LEDs contained in an electrically upstream one of the adjoininglight source parallel connections are connected to anodes of the LEDscontained in a downstream one, and cutting the pair of trunk paths suchthat anodes of the LEDs contained in the upstream one of the adjoiningparallel connections are separated from cathodes of the LEDs containedin the downstream one and that ends of each LED are not short-circuited.

According to yet another aspect of the present invention, there isprovided a light emitting apparatus comprising a plurality of lightsource assemblies each having a plurality of electrically connectedlight sources, wherein the plurality of light source assemblies are eacharranged to form a spiral extending toward a central portion from theirrespective starting points which are circumferentially spacedsubstantially evenly from each other in a periphery of a light emittingsurface of the light emitting apparatus. In this way, a surface lightemitting body can be made easily by using light source assemblies eachconstituted by joining a plurality of light sources arranged in a line.Particularly, if the plurality of light source assemblies comprise atleast two light source assemblies emitting lights of different colors,the light sources of different colors can be mixedly arrangedsubstantially evenly.

According to yet another aspect of the present invention, there isprovided a light emitting apparatus, comprising a plurality of LEDparallel connections each having a plurality of parallel connected LEDs,wherein the plurality of LED parallel connections are connected inseries, and wherein each LED is connected to an associated resistor inseries. In this light emitting apparatus, if a single LED suffers ashort-circuiting malfunction, a voltage is produced across the resistorconnected in series to the malfunctioning LED, and therefore, the endsof the LEDs connected in parallel with the malfunctioning LED are keptfrom short-circuiting and thus the light emission can be maintained.Thus, if a single LED suffers a short-circuiting malfunction,significant decrease in the amount of emitted light can be prevented.

According to still another aspect of the present invention, there isprovided a patterned conductor having a prescribed pattern and used forforming a light source assembly by electrically connecting a pluralityof light sources, wherein the patterned conductor comprises anexpandable portion at a prescribed longitudinal position. In this way,even after the light source assembly is fabricated, arrangementpositions of the light sources can be adjusted by deforming theexpandable portion. Further, it is possible to easily achieve variouslight source arrangements. For example, the arrangement of the lightsources may not be limited to straight and the direction of light sourcearrangement may be bent or offset. The patterned conductor preferablycomprises a deformation prohibiting portion for selectively allowingdeformation of the expandable portion. It is preferred that theexpandable portion and the deformation prohibiting portion are formed byblanking (or punching) because this can allow easy and efficientfabrication of these portions. In such a case, it is desirable thatdeformation of the expandable portion is enabled by cutting off thedeformation prohibiting portion so that the enabling can be easily done.In a case where the patterned conductor further comprises a pair oftrunk paths extending substantially in parallel in the longitudinaldirection, and the plurality of light sources are connected between thepair of trunk paths, the expandable portion and the deformationprohibiting portion can be formed by blanking a portion of the pair oftrunk paths. Alternatively, the expandable portion may have at least onecrease extending in a widthwise direction of the patterned conductor.

Other and further objects, features and advantages of the invention willappear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Now the present invention is described in the following with referenceto the appended drawings, in which:

FIG. 1 is a cross-sectional view showing a light emitting apparatusaccording to the present invention;

FIG. 2 is a cross-sectional view along the lines II-II in FIG. 1;

FIG. 3 is a perspective view of a light source assembly shown in FIG. 1;

FIGS. 4 a and 4 b are front views each showing an embodiment of atape-shaped patterned conductor;

FIG. 5 is a view for showing a state of the light emitting apparatus ofFIG. 1 under fabrication;

FIG. 6 shows a way of secondary processing of the tape-shaped patternedconductor for achieving a light emitting apparatus of a serial-parallelconnection type;

FIG. 7 shows a way of secondary processing of the tape-shaped patternedconductor for achieving a light emitting apparatus of a parallelconnection type;

FIG. 8 shows a way of secondary processing of the tape-shaped patternedconductor for achieving a light emitting apparatus of a serialconnection type;

FIG. 9 is a cross-sectional view showing a light emitting apparatus inthat the light source assembly of a serial connection type obtained bythe secondary processing shown in FIG. 8 is attached to a mounting board(holder);

FIG. 10 shows another embodiment of the secondary processing of thetape-shaped patterned conductor to form a light emitting apparatus of aserial connection type;

FIGS. 11 a and 11 b are cross-sectional views for showing different waysof attaching the light source assembly to the holder;

FIG. 12 is a front view showing an embodiment in which the light sourcesare arranged on a flat surface;

FIG. 13 is a cross-sectional view showing an embodiment in which thelight sources are arranged on a curved surface;

FIG. 14 is a front view showing an embodiment of a tape-shaped patternedconductor suitable for achieving a light emitting apparatus of a serialconnection type;

FIG. 15 shows a way of secondary processing of the patterned conductorshown in FIG. 14;

FIG. 16 is a perspective view showing an embodiment of a light sourceassembly according to the present invention;

FIG. 17 a is a cross-sectional view taken along the lines XVII-XVII inFIG. 16, and FIG. 17 b is a cross-sectional view corresponding to FIG.17 a and showing an embodiment utilizing a socket pin;

FIG. 18 is a plan view of a patterned conductor used in forming a lightsource assembly shown in FIG. 16;

FIG. 19 shows a way of secondary processing of the patterned conductorof FIG. 18 to form a light source assembly in which the light sourcesare connected in series-parallel connection;

FIG. 20 shows a way of secondary processing of the patterned conductorof FIG. 18 to form a light source assembly in which the light sourcesare connected in parallel;

FIG. 21 shows a way of secondary processing of the patterned conductorof FIG. 18 to form a light source assembly in which the light sourcesare connected in series;

FIG. 22 is a perspective view showing another embodiment of a lightsource assembly according to the present invention;

FIG. 23 is a top view of a socket without an LED;

FIG. 24 is a cross-sectional view showing the socket with the LEDinstalled therein;

FIG. 25 is a plan view of a patterned conductor used in forming thelight source assembly shown in FIG. 16;

FIG. 26 shows a way of secondary processing of the patterned conductorshown in FIG. 25 to form a light source assembly in which the lightsources are connected in series-parallel connection;

FIG. 27 shows a way of secondary processing of the patterned conductorshown in FIG. 25 to form a light source assembly in which the lightsources are connected in parallel;

FIG. 28 shows a way of secondary processing of the patterned conductorshown in FIG. 25 to form a light source assembly in which the lightsources are connected in series;

FIG. 29 is a perspective view showing a modified embodiment of the lightsource assembly shown in FIG. 22;

FIG. 30 a perspective view showing another modified embodiment of thelight source assembly shown in FIG. 22;

FIG. 31 a perspective view showing a yet another modified embodiment ofthe light source assembly shown in FIG. 22;

FIG. 32 is a plan view of a patterned conductor used in forming thelight source assembly shown in FIG. 31;

FIG. 33 is a plan view showing a modified embodiment of the patternedconductor of FIG. 18 suitable for forming a light source assembly havinglight sources connected in series;

FIG. 34 is a plan view showing a modified embodiment of the patternedconductor of FIG. 25 suitable for forming a light source assembly havinglight sources connected in series;

FIG. 35 is a perspective view similar to FIG. 16 and shows anotherembodiment of a joint member;

FIG. 36 is a perspective view similar to FIG. 16 and shows yet anotherembodiment of a joint member;

FIG. 37 is an underside view of the light source assembly of FIG. 36;

FIG. 38 is a perspective view showing an embodiment in which the lightsource assembly of FIG. 36 is attached to a holder;

FIG. 39 is a perspective view of a light emitting apparatus using thelight source assembly of FIG. 36;

FIG. 40 is a cross-sectional view taken along the lines XL-XL in FIG.39;

FIG. 41 is a top plan view for schematically showing the light emittingapparatus of FIG. 39;

FIG. 42 a is a perspective view showing an embodiment of a light sourceassembly that uses a light emitting element assembly as a light source,and FIG. 42 b is a circuit diagram of the light emitting elementassembly shown in FIG. 42 a;

FIG. 43 a is a perspective view showing another embodiment of a lightsource assembly that uses a light emitting element assembly as a lightsource, and FIG. 43 b is a circuit diagram of the light emitting elementassembly shown in FIG. 43 a;

FIG. 44 is a plan view showing another embodiment of a tape-shapedpatterned conductor according to the present invention;

FIG. 45 is a perspective view showing a light source assembly using thepatterned conductor of FIG. 44 together with a holder for supporting thelight source assembly;

FIG. 46 is a schematic view showing the light source assembly of FIG. 45flexed in a longitudinal direction;

FIG. 47 a is a partial plan view showing another embodiment of atape-shaped patterned conductor according to the present invention, FIG.47 b is a cross-sectional view taken along the lines A-A in FIG. 47 a,and FIG. 47 c is a partial plan view of a light source assembly formedby attaching chip-type LEDs and chip-type resistors to the connectiveconductor structure which in turn is formed by cutting off parts of thepatterned conductor of FIG. 47 a as required;

FIG. 48 a is a front view of a three-pole LED lamp, and FIG. 48 b is acircuit diagram of the three-pole LED lamp shown in FIG. 48 a;

FIG. 49 is a plan view of a tape-shaped patterned conductor suitable forforming a light source assembly by connecting a plurality of three-poleLED lamps shown in FIGS. 48 a and 48 b;

FIG. 50 is a plan view showing an example of a way of cutting off in thesecondary processing of the patterned conductor shown in FIG. 49 to forma connective conductor structure having a prescribed circuit pattern;

FIG. 51 is a circuit diagram of a light source assembly formed by usingthe connective conductor structure that is made following the way ofsecondary processing shown in FIG. 50;

FIG. 52 a is an upper perspective view of a four-pole LED lamp, FIG. 52b is a lower perspective view of the four-pole LED lamp of FIG. 52 a,and FIG. 52 c is a circuit diagram thereof;

FIG. 53 is a plan view of a tape-shaped patterned conductor suitable forforming a light source assembly by connecting a plurality of four-poleLED lamps shown in FIGS. 52 a-52 c;

FIG. 54 is a plan view showing an example of a way of cutting off in thesecondary processing of the patterned conductor shown in FIG. 49 to forma connective conductor structure having a prescribed circuit pattern;

FIG. 55 is a circuit diagram of a light source assembly formed by usingthe connective conductor structure that is made following the way ofsecondary processing shown in FIG. 54;

FIG. 56 is a partial plan view showing another embodiment of a patternedconductor according to the present invention;

FIG. 57 shows a way of secondary processing of the patterned conductorshown in FIG. 25 for forming a light source assembly in that the lightsources are connected in series and the trunk paths can be used for heatdissipation;

FIG. 58 a is a plan view showing a patterned conductor suitable forforming a light source assembly having a reduced width, and FIG. 58 b isa plan view showing an end conductor for allowing conductive pins to anend of the patterned conductor shown in FIG. 58 a;

FIG. 59 is a perspective view showing a light source assembly having aninsulating sheet attached to its surface on which the light sources aremounted;

FIG. 60 a is a partial perspective view showing a way of attaching thelight source assembly to a holder, and FIG. 60 b is a cross-sectionalview of the light source assembly attached to the holder;

FIG. 61 is a cross-sectional view showing another embodiment ofattaching the light source assembly to the holder;

FIGS. 62 a-62 c schematically show a manufacturing process of thepatterned conductor and light source assembly using photo-etching;

FIG. 63 a is a partial plan view of a patterned conductor suitable forforming a light source assembly having light sources arranged in tworows, and FIG. 63 b is a partial plan view showing an example ofsecondary processing of the patterned conductor;

FIG. 64 is a partial plan view suitable for forming a light sourceassembly having light sources arranged in four rows;

FIG. 65 is a circuit diagram showing a preferred embodiment of an LEDcircuit suitable for use as a traffic light;

FIG. 66 is a circuit diagram showing another preferred embodiment of anLED circuit suitable for use as a traffic light;

FIG. 67 is a schematic view showing a way of using a light sourceassembly to form a surface light emitting apparatus having an electricconnection as shown in FIG. 66;

FIG. 68 is a schematic partial plan view showing an embodiment of alight source assembly having an electric connection as shown in FIG. 65and adapted to provide a linear light emitting apparatus containing LEDsarranged in a line;

FIG. 69 is a schematic partial plan view showing another embodiment of alight source assembly having an electric connection as shown in FIG. 65and adapted to provide a linear light emitting apparatus containing LEDsarranged in a line;

FIG. 70 is a partial plan view showing another embodiment of a patternedconductor;

FIG. 71 is a partial plan view showing an example of a light sourceassembly formed by using the patterned conductor shown in FIG. 70;

FIG. 72 a is a schematic view of a light emitting apparatus formed byusing the light source assembly shown in FIG. 71, and FIG. 72 b is across-sectional view taken along the lines b-b in FIG. 72 a;

FIG. 73 is a partial plan view showing another example of a secondaryprocessing of the patterned conductor shown in FIG. 56;

FIG. 74 is a partial plan view of a light source assembly formed byusing the patterned conductor applied with the secondary processingshown in FIG. 73;

FIG. 75 is a schematic partial plan view showing an embodiment of alight source assembly for providing a linear light emitting bodycontaining two rows of LEDs each having electric connection as shown inFIG. 65;

FIG. 76 is a schematic diagram showing a preferred arrangement of aplurality of light source assemblies used for forming a surface lightemitting body;

FIG. 77 is a schematic diagram showing another preferred arrangement ofa plurality of light source assemblies used for forming a surface lightemitting body;

FIG. 78 is a schematic diagram showing yet another preferred arrangementof a plurality of light source assemblies used for forming a surfacelight emitting body;

FIG. 79 is a schematic view showing an exemplary state of light sourceassembly in use;

FIG. 80 is a perspective view showing an embodiment of a light emittingapparatus using a light source assembly according to the presentinvention and adapted for forming an automobile lamp;

FIG. 81 is a perspective view showing the light source assembly used inthe light emitting apparatus, the light source assembly being shown in astate before bending;

FIG. 82 is an end view of the light source assembly shown in FIG. 81;

FIG. 83 is a partial plan view of an embodiment of a patterned conductorsuitable for forming the light source assembly shown in FIG. 81;

FIG. 84 a is a partial plan view showing another embodiment of apatterned conductor for allowing adjustment of the position of LEDs, andFIG. 84 b is a view similar to FIG. 84 a and illustrates the parts to beremoved in a used state by hatching lines;

FIGS. 85 a and 85 b are partial plan views showing examples of deformedstates of the light source assembly formed by using the patternedconductor shown in FIG. 84 a;

FIG. 86 a is a partial plan view showing another embodiment of apatterned conductor having an extendable portion, and FIG. 86 b is apartial plan view showing an example of a deformed state of a lightsource assembly using the patterned conductor;

FIG. 87 a is a partial plan view showing yet another embodiment of apatterned conductor having an extendable portion, FIG. 87 b is a frontview of the patterned conductor shown in FIG. 87 a, and FIG. 87 c is apartial plan view showing an example of a deformed state of a lightsource assembly using the patterned conductor;

FIG. 88 a is a partial plan view showing still another embodiment of apatterned conductor having an extendable portion, FIG. 88 b is a frontview of the patterned conductor shown in FIG. 88 a, and FIG. 88 c is apartial plan view showing an example of a deformed state of a lightsource assembly using the patterned conductor; and

FIG. 89 a is a partial plan view showing yet another embodiment of apatterned conductor, and FIG. 89 b is a partial plan view showing alight source assembly using the patterned conductor of FIG. 89 a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, embodiments of the present invention are explainedwith reference to the drawings.

FIG. 1 is a front cross-sectional view showing a preferred embodiment ofa light emitting apparatus according to the present invention. As shown,the light emitting apparatus comprises a plurality of light emittingdiodes (LEDs) 1 as light sources, and each LED 1 consists of abullet-type LED (or lamp-type LED) having a pair of parallel lead wires3 functioning as electric connection terminals and a packaging part (ormain body) 1 a shaped like a bullet. The light sources 1 are arranged ina row along a surface of a mount board (holder) 2 in a directionperpendicular to the lead wires 3. The light sources 1 areseries-parallel connected by a connective conductor structure 4 thatextends in a direction of arrangement of the light sources 1, i.e.,series connections of multiple light sources 1 are connected in parallelwith each other, to form a light source assembly 6. The series-parallelconnection has a benefit that it can be connected to a commercial powersource without using a step-down transformer by suitably adjusting anumber of light sources connected in series as well as that an arbitrarynumber of light sources can be utilized by parallel-connecting aplurality of series connections of light sources (or series blocks).

As shown in the drawing, the connective conductor structure 4 comprisesa first and second trunk paths 11, 12 supplied with a power voltage andeach connected to the lead wires 3 of prescribed light sources 1, and aplurality of coupling pieces 5 for coupling between the lead wires 3 ofadjacent light sources 1. Each coupling piece 5 has a pair of connectionparts 9 and engages base portions 3 a of the lead wires 3 of adjacentlight sources 1 via the pair of connection parts 9. The first and secondtrunk paths 11, 12 are connected to the base portions 3 a of the leadwires 3 of associated light sources 1 via branch paths 13, 14,respectively, and the connection parts 9 coupled to the branch paths.The first trunk path 11, which is closer to the main body 1 a of thelight sources 1, is formed with cuttings (or slits) 15 extending in awidthwise direction and whereby the first trunk path 11 assumes atortuous shape. In other words, portions of the first trunk path 11longitudinally aligned with the light source mount positions curveconvexly. To secure the light source assembly 6 constructed as above tothe mount board 2, end portions 3 b of the lead wires 3 are insertedinto mount holes 7 formed in the mount board 2.

FIG. 2 is a cross-sectional view taken along the lines II-II in FIG. 1,and FIG. 3 is a perspective view showing the light source assembly 6 ofFIG. 1. In FIG. 3, the main bodies 1 a of the light sources 1 are shownin broken lines for ease of illustration. Also in this drawing, atape-shaped patterned conductor 16, from which the connective conductorstructure 4 is made as described in detail below, is shown in brokenlines.

As best shown in FIG. 3, in this embodiment, each connection part 9 hasa plate-shaped member such that the connection part 9 can be engaged tothe associated lead wire 3 by cramping the lead wire 3 or bending theconnection part 9 to sandwich the lead wire 3. The securing of theconnection part 9 to the lead wire 3 may be achieved by various meansother than cramping, such as spot welding or engagement using elasticengaging pieces, but it should be noted that cramping can bring aboutsuch benefits as allowing continuous processing using a progressivepress machine, eliminating use of solder, or eliminating concern aboutthe heat deteriorating the light sources (LEDs) 1.

As shown in FIGS. 2 and 3, the connective conductor structure 4 is bentat positions substantially corresponding to a bottom of the cuttings 15of the first trunk path 11 and at positions substantially correspondingto an intersection between the branch paths 14 and the coupling pieces 5along bending lines extending in a longitudinal direction. This placesthe first and second trunk paths 11, 12 at an angle with respect to theconnection parts 9, which extend along the lead wires 3, when seen inthe cross-sectional view of FIG. 2. Thus, by bending the widthwisecross-sectional shape (i.e., a cross-sectional shape taken along a planeperpendicular to the longitudinal direction) of the connective conductorstructure 4, it is possible not only to prevent interference between thelight source main bodies 1 a and the first trunk path 11 but also toachieve a simple structure with no insulating treatment applied to theconnective conductor structure 4 while preventing the first and secondtrunk paths 11, 12 from contacting the lead wires 3 of the light sources1 to inadvertently make a short-circuit. The connective conductorstructure 4 not covered by an insulating material and hence exposed tothe air can improve heat dissipation and thus favorably allowshigh-density arrangement of the light sources 1. The bending of theconnective conductor structure 4 can limit longitudinal flexion thereof,and thus allows an easier handling when attaching it to the mount board2. Further, the bending can cause the end portions 3 b of the lead wires3 to protrude towards the mount board 2 so that they can be easilyinserted into the mount holes 7 of the mount board 2.

According to the present invention, the connective conductor structure 4described above can be obtained by carrying out secondary processing ofa tape-shaped patterned conductor 16, i.e., cutting off parts of thetape-shaped patterned conductor 16 as required when the patternedconductor 16 is attached to the light sources 1, in which the patternedconductor 16 is beforehand formed with a circuit pattern that can beused commonly in series, parallel and series-parallel connections,preferably by press working (blanking) a conductive plate material. Asdescribed in detail later, by changing the parts to be cut off in thetape-shaped patterned conductor 16, it is possible to connect the lightsources 1 in any of series, parallel or series-parallel connections.

FIG. 4 a is a front view showing an embodiment of the tape-shapedpatterned conductor 16 before the secondary processing. In this drawing,parts corresponding to those of the connective conductor structure 4shown above are denoted with same reference numerals. In FIG. 4 a, theconnection parts 9 to be engaged with the lead wires 3 of the lightsources 1 are shown in a state before being bent to engage with the leadwires 3. The connection parts 9 are connected by a longitudinallyextending interconnection path 10, and the first and second trunk paths11, 12 are disposed on either side of the tape-shaped patternedconductor 16 so as to interpose the interconnection path 10 and theconnection parts 9 therebetween. The first and second trunk paths 11, 12are connected to the interconnection path 10 in a widthwise direction bythe plurality of branch paths 13, 14.

As mentioned above, the tape-shaped patterned conductor 16 is appliedwith a secondary processing of cutting off parts as required dependingon various usages to make the connective conductor structure 4 thatrealizes a circuit with a desired connection pattern. It, will bepreferable if such a secondary processing is carried out at the sametime when the tape-shaped patterned conductor 16 and the light sources1, which are held in a radial taping, are attached together by aprogressive press machine because it can simplify the manufacturingprocess. For this reason, in the tape-shaped patterned conductor 16shown in FIG. 4 a, the second trunk path 12, which is away from thelight source main bodies 1 a, is formed with pilot holes 18 for engagingpilot pins of the progressive press machine (not shown) to thereby alignthe tape-shaped patterned conductor 16 with the light sources 1 and thusensure that the light sources 1 are mounted at predetermined positionson the tape-shaped patterned conductor 16. Alternatively, as in atape-shaped patterned conductor 16 shown in FIG. 4 b, it is possible toprovide a side frame 19 connected to the second trunk path 12 via joints20, and form the pilot holes 18 for engaging the pilot pins of theprogressive press machine in the side frame 19, although the additionalside frame 19 will necessitate a larger amount of material compared withthe embodiment of FIG. 4 a.

The tape-shaped patterned conductor 16 can be obtained by press working(more specifically, blanking) a conductive plate material. Specifically,cut-out holes 21 are first formed such that the cut-out holes 21 definethe connection parts 9 projecting from the interconnection path 10 in adirection along the lead wires 3, divide the first trunk path 11 fromthe interconnection path 10, and define the branch paths 13 connectingtherebetween. The cut-out holes 21 also provide a space into which atool for bending the connection parts 9 can be inserted. Then the firsttrunk path 11 is formed with the cuttings 15. Further, cut-out holes 22for dividing the interconnection path 10 from the second trunk path 12as well as defining the branch paths 14 connecting between them areformed. The branch paths 13, 14 for connecting the first and secondtrunk paths 11, 12 to the interconnection path 10 are preferably formedat positions offset from the lead wires 3 so that inadvertent cutting ofthe lead wires 3 can be prevented when cutting off the branch paths 13,14. This can allow a proper length of the lead wires 3 to project towardthe mount board 2, for example, whereby when the light source assembly 6is attached to the mount board 2, the lead wires 3 can be inserted intothe mount holes 7 in the mount board 2 to achieve a secure mounting ofthe light source assembly 6 (see FIG. 1).

The tape-shaped patterned conductor 16 is flexible and can be curved orbent, and this allows the patterned conductor 16 to be wound in a coilor folded in an accordion fashion so that it can be easily stored,transported or packaged.

FIG. 5 shows a state of the light emitting apparatus of FIG. 1 during amanufacturing process. The light sources 1 each consist of a bullet-typeLED lamp having a pair of lead wires 3 extending in the same direction,and are held in the radial taping so as to be arranged in a directionperpendicular to the direction of extension of the lead wires 3. Acarrier tape 25 for the radial taping consists of a pair of tape members25 a, 25 b which are stuck together, and the lead wires 3 are heldbetween the pair of tape members 25 a, 25 b to retain the light sources1. Like the tape-shaped patterned conductor 16, the carrier tape 25 isformed with pilot holes 26 so that aligning the pilot holes 18, 26 ofthe tape-shaped patterned conductor 16 and carrier tape 25 can achievean axial alignment of the connection parts 9 formed in the patternedconductor 16 and the lead wires 3 of the light sources 1 held by thecarrier tape 25. The connection parts 9 are brought into engagement withthe lead wires 3 held by the tape 25, and then, the secondary processingof the tape-shaped patterned conductor 16 is carried out. It should benoted, that when the lead wires 3 and the connection parts 9 areengaged, the tape-shaped patterned conductor 16 need be bent along thelongitudinal bending line so as to prevent the first trunk path 11 ofthe patterned conductor 16 from interfering with the main bodies 1 a ofthe light sources 1.

It will be preferable in view of high production efficiency and easyhandling to prepare the tape-shaped patterned conductor 16 wound in acoil, and then carry out the above described engagement between thepatterned conductor 16 and the light sources 1 while unwinding thepatterned conductor 16 in the progressive press machine. Since the firsttrunk path 11 of the tape-shaped patterned conductor 16 of the presentinvention is formed with the widthwise cuttings 15 so that the firsttrunk path 11 comprises a plurality of convexly curved portions, it ispossible that the convexly curved portions in an unwound part of thetape-shaped patterned conductor 16 can be bent individually although therest of the patterned conductor 16 is still wound in coil, to therebyavoid interference between the main bodies 1 a of the light sources 1and the first trunk path 11 of the patterned conductor 16.

FIG. 6 shows a way of secondary processing of the tape-shaped patternedconductor 16 for forming the light emitting apparatus of aseries-parallel connection type shown in FIG. 1. In this drawing, theparts to be cut off are shown by hatching. As shown, parts 27 of theinterconnection path 10 located between respective pairs of connectionparts 9 each corresponding to a pair of lead wires 3 of a same lightsource 1 are removed. Further, the branch paths 13, 14 except for thoselocated at ends of a range corresponding to each series connection ofthe light sources 1 (series block) are cut off. Also, parts 28 of theinterconnection path 10 between adjoining series blocks are-cut off. Itwill be understood that in this way, the coupling pieces 5 of theconnective conductor structure 4, for example, can be formed from theinterconnection path 10 of the tape-shaped patterned conductor 16. Asdescribed above, in the secondary processing, the tape-shaped patternedconductor 16 (or connective conductor structure 4) is bent along thelongitudinal bending lines on either side of the interconnection path 10and secured to the lead wires 3 preferably by cramping them with theconnection parts 9. In order to facilitate the bending, it may bepossible to beforehand provide the tape-shaped patterned conductor 16with a notch extending along the bending line. The tape-shaped patternedconductor 16 can be severed at appropriate points such that theresulting light source assembly 6 has a proper length that is easy tohandle. The secondary processing of the tape-shaped patterned conductor16 that can comprise the steps of cutting off, bending, cramping andsevering as described above can be carried out by a progressive pressmachine. It should be noted that the bending of the tape-shapedpatterned conductor 16 on a side of the second trunk path 12 that isformed with the pilot holes 18 for engaging the pilot pins of theprogressive press machine should be done at a final stage of theprogressive press machine. Alternatively, the bending may be done afterthe light source assembly 6 has been removed from the progressive pressmachine.

The parts 27 of the interconnection path 10 located between respectivepairs of connection parts 9 each for a pair of lead wires 3 of a samelight source 1 need be cut off in any connection pattern, and therefore,the tape-shaped patterned conductor 16 may not comprise the parts 27.However, with the parts 27, the connection parts 9 can be steadilysupported when engaging the connection parts 9 with the lead wires 3.

FIG. 7 shows a way of secondary processing of the tape-shaped patternedconductor 16 for making a light source assembly of a parallel connectiontype. As in the above example, the parts to be cut off are shown byhatching. In addition to the parts 27 of the interconnection path 10located between respective pairs of connection parts 9 eachcorresponding to a pair of lead wires 3 of a same light source 1, parts29 of the interconnection path 10 between connection parts 9corresponding to the lead wires 3 of adjoining light sources 1 areremoved. Further, in a similar manner as in the above example, thepatterned conductor 16 is bent along the longitudinal bending lines oneither side of the interconnection path 10, and the connection parts 9are engaged to the lead wires 3 by cramping. In this connection pattern,the branch paths 13, 14 are left without being cut off.

FIG. 8 shows a way of secondary processing of the tape-shaped patternedconductor 16 for making a light source assembly of a series connectiontype. As in the above examples, the parts to be cut off are shown byhatching. As seen, all the parts 27 of the interconnection path 10located between respective pairs of connection parts 9 each for a pairof lead wires 3 of a same light source 1 are cut off, and further, allthe branch paths 13, 14 as well as the pair of trunk paths 11, 12 arecut off, leaving the mutually separate coupling pieces 5 behind. Eachcoupling piece 5 comprises a main body extending in the directionperpendicular to the lead wires 3, and the pair of connection parts 9extend from either end portions of the main body in the direction alongthe lead wires 3. The lead wires 3 of each light source 1 areelectrically and mechanically connected to the lead wires 3 of theadjacent light source 1 via the coupling pieces 5 to form the lightsource assembly. Thus, in this embodiment; the connective conductorstructure 4 is formed only by the coupling pieces 5;

FIG. 9 is a cross-sectional view showing a light emitting apparatus inthat a series connection type light source assembly 32 obtained by thesecondary processing shown in FIG. 8 is attached to the mount board(holder) 2. In this embodiment, the lead wires 3 at both ends are notengaged with the coupling piece 5, and the other lead wires 3 are cut atthe same time when the coupling pieces 5 are separated so that the leadwires 3 do not protrude toward the mount board 2. The lead wires 3 atboth ends are cut at a desired length and inserted into mount holes 33formed in the mount board 2 and connected to a power supply.

FIG. 10 shows another way of secondary processing of the tape-shapedpatterned conductor 16 for making a light emitting assembly of a seriesconnection type. As in the above embodiment, the parts to be cut off areshown by hatching. As shown, the parts 27 of the interconnection path 10located between respective pairs of lead wires 3 of a same light source1 are removed. Further, in this embodiment, the branch paths 13connected to the first trunk path 11 are cut off except for the onelocated at one end (right end in this drawing). Also, the branch paths14 connected to the second trunk path 12 are cut off except for the onelocated at the other end (left end in the drawing). In contrast to theabove embodiment, this embodiment retains the first and second trunkpaths 11, 12 to which the supply voltage may be applied.

FIG. 11 a is a cross-sectional view showing a different example of anattachment of the light source assembly to the holder. In thisembodiment, coupling pieces 35 of a light source assembly 37 are formedon either end thereof with a protrusion extending toward the mount board2 such that each protrusion is aligned with the end of an associatedlead wire 3. The end of the lead wire 3 and the protrusion of thecoupling piece 35 are together inserted into an associated mount hole 36formed in the mount board 2 to thereby support the light source assembly37 on the mount board 2. Such a coupling piece 35 can be formed byproviding the branch paths 14 of the tape-shaped patterned conductor 16of FIG. 4 a not only for one, but for both of the pair of connectionparts 9 associated with each light source 1 so as to be aligned in thelongitudinal direction, and in the secondary processing of thetape-shaped patterned conductor, cutting the branch paths 14 at theirroot portion near the second trunk path 12 together with the lead wiresof the light sources 1 attached to the tape-shaped patterned conductor.It may be possible that one for every several lead wires 3 may protrudeto be inserted into the mount holes 36, and in such a case, the numberof lead wires 3 inserted in the mount holes 36 can be determined so asto ensure proper support of the light source assembly 37 on the mountboard 2 taking into account the rigidity of the lead wires 3 andcoupling pieces 35. Further, as shown in FIG. 11 b, the mount holes 36may be recesses 36′ instead of through-holes. Such recesses 36′ can beformed at a unitary part when the mount board 2 is made by molding, forexample, or can be formed by drilling after the molding of the mountboard 2. Or the recesses 36′ can be formed by providing a plurality ofprojections on the mount board 2.

FIGS. 12 and 13 show examples of arrangement of the light sources 1 onthe holder. FIG. 12 shows an example in which the light sources arearranged on a plane. Specifically, on a surface of a flat holder (mountboard) 41, a light source assembly 42 having a plurality of lightsources 1 connected by the above-mentioned connective conductorstructure 4 are bent at appropriate portions to form a loop such thatthe line of the light sources of the light source assembly 42 representsa profile of a letter. FIG. 13 shows an example in that the lightsources 1 are arranged on a curved surface, and specifically, a lightsource assembly 52 having a plurality of light sources 1 connected bythe above-mentioned connective conductor structure 4 is wound around aholder 51 having a closed shape in cross-section. It is also possible toform a surface light emitting body by arranging light sources densely ona surface of a holder.

FIG. 14 is a front view showing a modified embodiment of the patternedconductor suitable for forming a series connection of light sources, andFIG. 15 shows a way of secondary processing carried out when attachingthe patterned conductor to the light sources (parts to be cut off areshown by hatching). In these drawings, parts similar to those in FIG. 4a or FIG. 6 are denoted with same numerals and detailed explanationthereof is omitted. As shown in the drawings, a patterned conductor 16″for forming a series connection of light sources comprises aninterconnection path 10′ formed with pilot holes 18′ for alignment ortransportation in the manufacturing line, and does not poses the firstand second trunk paths 11, 12 and the branch paths 13, 14 for connectingthe first and second trunk paths 11, 12 to the interconnection path 10as shown in FIG. 4, and accordingly has a narrower width. In this way,an amount of material not used in the final light source assembly can bereduced to significantly lower the manufacturing cost.

In the above embodiments, LEDs are used as light sources. However, thepresent invention should not be limited to them, and may be similarlyapplied to the lamps having lead wires such as cap-less miniature lamps.

As described above, according to the embodiments of the presentinvention, various light source assemblies having different light sourceconnection patterns can be formed in the same manufacturing line byusing a tape-shaped patterned conductor formed with a commonly usableprescribed circuit pattern, whereby advantageously reducing themanufacturing cost of the light emitting apparatus using such a lightsource assembly. The light sources are unitarily connected in the lightsource assembly before being attached to the holder, and thus variouslight source arrangements can be easily achieved. Further, since nocomplicated machining processes are required in preparing the holder a,it is possible to suppress increase in the manufacturing cost even whena small amount of light source assemblies of various types aremanufactured.

In the above embodiments, each light source has a pair of substantiallyparallel lead wires, which extend along a primary surface of theconnective conductor structure (or patterned conductor). However, theremay be a case where it is desired to attach the light sources such thatthe lead wires extend substantially perpendicular to the primary surfaceof the connective conductor structure or where the light source consistsof a so-called chip-type LED having no lead wires. The embodiments beloware suitable for such cases.

FIG. 16 is a partial perspective view showing another preferredembodiment of a light source assembly according to the presentinvention. As shown, the light source assembly 101 uses a plurality oflight emitting diodes (LEDs) 102 as light sources, and each LED 102consists of a bullet-type LED (or lamp-type LED) having a pair ofparallel extending lead wires 103. The LEDs 102 are arranged in adirection perpendicular to the lead wires 103, and electricallyconnected by a substantially plate-like connective conductor structure104 extending in the direction of arrangement of the LEDs. In the shownembodiment, the LEDs 102 are in a series-parallel connection (i.e., aplurality of series connections of LEDs are connected in parallel), butas described later, may be in a series connection or parallel connectiondepending on the configuration of the connective conductor structure104.

The connective conductor structure 104 has first and second trunk paths111, 112 extending in a longitudinal direction and applied with a powersupply voltage, and arranged between the pair of trunk paths 111, 112are light source attachment portions 105 for connection with the leadwires 103 of the LEDs 102 and an interconnection path 110 for connectingthe light source attachment portions 105 in the longitudinal direction.As shown in the drawing, each light source attachment portion 105 has apair of terminal connection parts 109 for engagement with the pair oflead wires (terminals) 103 of an associated one of the LEDs 102, and inthis embodiment, the pair of terminal connection parts 109 are spacedfrom each other in the longitudinal direction. The first and secondtrunk paths 111, 112 are electrically connected to the interconnectionpath 110 at predetermined positions by branch paths 113, 114 extendingin a lateral (widthwise) direction, and in the shown embodiment, form aconductor pattern connecting the LEDs 102 in a series-parallelconnection. The interconnection path 110 and the first and second trunkpaths 111, 112 are mechanically joined by widthwise-extending insulatingjoint members 115, which are preferably formed by insert molding, sothat they are held in a unit.

Each terminal connection part 109 of the connective conductor structure104 is formed with a cross-shaped hole 116 so that inserting the leadwire 103 into the hole 116 can achieve mechanical/electrical connectionbetween the LED 102 and the connective conductor structure 104. Thecross-shape of the hole 116 provides four internally extendingprojections, which flex as the lead wire 103 is pushed into the hole116, to thereby securely hold the lead wire 103. As best shown in FIG.17 a, which is a cross-sectional view taken along the lines XVII-XVII inFIG. 16, after each lead wire 103 is inserted into the associated hole116, extensions 117, which are provided on both sides of the hole 116and extend in the widthwise direction, are bent to sandwich or cramp thelead wire 103 therebetween. This contributes to reliably preventinginadvertent escape of the lead wire 103 from the hole 116. After beingcramped by the extensions 117, the lead wires 103 are cut so as to havean appropriate length. The lead wires 103 may have been cut to aprescribed length beforehand. As shown, the lead wires 103 may beinserted into associated recesses or holes 124 formed in a mount board(holder) 123 to attach the light source assembly 101 to the holder 123

Other than inserting the lead wire 103 into the hole 116 and crampingthe lead wire 103 by the extensions 117, the connection between the leadwire 103 and the terminal connection part 109 can be accomplished byspot welding, supersonic welding, laser welding, etc. It should benoted, however, above described cramping may have advantages such asenabling continuous processing by the progressive pressing machine,eliminating the use of solder and eliminating concern about the heatthat would impart undesirable effects on the LEDs 102. It may bepossible to adopt both the insertion of the lead wire 103 into the hole116 and the laser welding. In such a case, the hole 116 having theinward projections as shown in the drawing can contribute to achievingmore reliable laser welding because the inward projections are bent andpressed against the lead wire 103 as the lead wire 103 is inserted intothe hole 116 and thus can increase the contact area. It may be possibleto make a cut in a part of the interconnection path 110 adjacent thehole 116 so as to form a tongue piece, and bend the tongue piece suchthat the tongue piece and the pair of extensions 117 cramp the lead wire103 from three directions.

Further, as shown in a cross-sectional view of FIG. 17 b, a so-called“socket pin” 125 may be inserted into the hole 116 for connection withthe lead wire 103. A socket pin comprises a conductor having a pinportion (protruding or male portion) with a socket portion (recessed orfemale portion) formed on a back side of the pin portion, and may beavailable as a PD series provided from Mac-Eight, for example. Bypushing the pin portion into the hole 116 beforehand, the electricalconnection between the LED and the connective conductor structure 104can be readily achieved by inserting the lead wire 13 into the socketportion of the socket pin.

According to the present invention, the connective conductor structure104 as described above can be obtained by cutting off parts of apatterned conductor as required in a secondary processing thereof, wherethe patterned conductor is beforehand formed with a circuit pattern thatcan be commonly used in series, parallel or series-parallel connectionspreferably by press working (blanking) a conductive plate material in aprimary processing. In this way, by changing the parts to be cut off inthe patterned conductor, it is possible to connect the light sources 102in any of series, parallel or series-parallel connections.

FIG. 18 is a partial plan view showing a preferred embodiment 120 of thepatterned conductor before the secondary processing. In this drawing,parts corresponding to those of the connective conductor structure 104shown above are denoted with same reference numerals. As shown in thedrawing, the patterned conductor 120 has a longitudinal tape-like shapewith a self-supportive feature (or its parts are unitary), wherein theinterconnection path 110 extends in the longitudinal direction toconnect the light source attachment portions 105. The first and secondtrunk paths 111, 112 are disposed on either side of the patternedconductor 120 so as to interpose the interconnection path 110 and thelight source attachment portions 105 therebetween. Each terminalconnection part 109 of each light source attachment portion 105 isconnected to the first and second trunk paths 111, 112 via associatedbranch paths 113, 114. The interconnection path 110 comprises aplurality of connection paths 121 each coupling a pair of terminalconnection parts 109 that are to engage lead wires 103 of adjoining,different LEDs 102 (i.e., that are contained in adjoining light sourceattachment portions 105). The joint members 115 formed by insert moldingcan be disposed on the connection paths 121 (see FIG. 16). In formingthe joint members 115, a part of each joint member 115 aligned with theassociated connection paths 121 is formed with a hole 119 to expose theconnection path 121 (a part of the connection path 121 exposed by thehole 119 is called a bridge portion 121A (see FIGS. 19-21)). In thisway, after the joint members 115 are formed, a punch of a press machine(not shown) can be inserted into the hole 119 to cut off the bridgeportion 121A to whereby separate the terminal connection parts 109 thatwere connected by the connection path 121.

As described above, the patterned conductor 120 is converted into theconnective conductor structure 104 having a circuit with a prescribedconnection pattern by carrying out the secondary processing to cut offparts as required depending on usages, and the secondary processing canbe preferably conducted after the trunk paths 111, 112 and theinterconnection path 110 are joined together by the joint members 115formed by insert molding. By doing so, it is possible to prevent theparts of the resulting connective conductor structure 104 from beingseparated apart. It will be efficient if such formation of the jointmembers 115 by insert molding as well as secondary processing of thepatterned conductor 120 are carried out in a continuous manufacturingline. Therefore, in order to allow transportation/alignment in themanufacturing line, the second trunk path 112 is formed with pilot holes118 for engagement with pilot pins of a progressive press machine (notshown), for example.

The patterned conductor 120 as described above can be preferablyobtained by press working (more specifically, blanking) a conductiveplate material made of metal such as aluminum or copper. Aluminum is notused in printed circuit board because of its poor affinity with solder,but has an advantage of a low specific gravity (about one third of thatof copper) and thus is suitable for making a lighter product. Further,aluminum is also preferred in view of having a high thermal conductivity(several times that of copper) as well as a high electric conductivity.Also, while the copper film on a printed circuit board is about 35 μm,the patterned conductor can be as thick as 100-300 μm, allowing a largerelectric current to flow. This is also favorable in view of heatdissipation. The patterned conductor 120 may be alternatively formed byphoto-etching the conductive plate material, or cutting the same bymeans of wire-cutting, laser or electrical discharge machining.Die-casting such as magnesium molding may also be used. The patternedconductor 120 is flexible and can be freely curved or bent, and thus,can be wound in a coil or folded in an accordion fashion so that it canbe easily stored, transported or packaged.

FIGS. 19-21 show ways of secondary processing of the patterned conductor120 for connecting the LEDs 102 in series-parallel, series, and parallelconnections, respectively. In these drawings, parts to be cut off areshown by hatching. Further, in order to help understand the positions tobe cut off, the joint members 115 having the hole 119 are shown inbroken lines.

The example of FIG. 19 provides a connective conductor structure thatcan connect a plurality of series connections of three LEDs 102 (seriesblocks) in parallel between the trunk paths 111, 112. Specifically, thebridge portions 121A of the connection paths 121 located betweenadjoining series blocks are cut off, and the connection paths 121coupling the terminal connection parts 109 within each series blockremain intact. The branch paths 113, 114 within each series block arecut off except for a branch path 113 connecting to the first trunk path111 at one end and a branch path 114 connecting to the second trunk path112 at the other end. It should be understood that the number of LEDs102 contained in each series block can be varied by changing the removedbranch paths 113, 114 and bridge portions 121A, and thus is not limitedto three. In the example of FIG. 19, the bridge portions 121A connectingthe adjoining LEDs 102 contained in the same series block (or connectingthe terminal connection parts contained in the adjoining light sourceattachment portions 105) remain uncut. However, as shown by broken linesin the perspective view in FIG. 16, when a resistor 122 is connected tothe interconnection path 110 by spot welding or laser welding, forexample, to insert the resistor 122 between adjoining LEDs 102, thebridge portion 121A to be located between a pair of terminals of theresistor 122 may be cut off. Similarly, as also shown by broken lines,when the resistor 122 is connected between the interconnection path 110and the second trunk path 112, the branch path 114 at the correspondingposition should be cut off. This similarly applies to the case where aresistor is connected between the interconnection path 110 and the firsttrunk path 111.

In an example of FIG. 20, the bridge portions 121A are all cut off, andthe branch paths 113, 114 are cut off such that one of the pair ofterminal connection parts 109 connected to each LED 102 (or in a samelight source attachment portion 105) is connected to the trunk path 111while the other is connected to the trunk path 112. This provides aconnective conductor structure for connecting the LEDs 102 mounted tothe light source attachment portions 105 in parallel between the trunkpaths 111, 112.

In an example of FIG. 21, all of the branch paths 113, 114 are cut offwhile the bridge portions 121A are all left uncut so that a seriesconnection of the LEDs 102 is formed between the trunk paths 111, 112.It can be said that each connection path 121 and the pair of terminalconnection parts 109 connected by the connection path 121 form acoupling piece for connecting adjacent LEDs 102. In the light sourceassembly 101 comprising thus-formed connective conductor structure forconnecting the LEDs 102, the supply voltage may be applied to the leadwires 103 of the LEDs 102 positioned at the ends of the LED seriesconnection, for example, without using the trunk paths 111, 112.However, it may be also possible to retain appropriate branch paths 113,114 so as to connect the LED series connection to the trunk paths 111,112, whereby the LED series connection is supplied with a voltage viathe trunk paths 111, 112 connected to the power supply. Only one of thetrunk paths 111, 112 may be used for such connection to the powersupply.

As described above, according to the preferred embodiments of thepresent invention, connective conductor structures 104 having variousconnection patterns (and the light source assembly 101 using them) canbe formed from the commonly used patterned conductor by varying the cutoff branch paths 113, 114 and bridge portions 121 a. The secondaryprocessing of the patterned conductor for forming the connectiveconductor structure 104 can be preferably achieved by press working inwhich selection of the branch paths 113, 114 and bridge portions 121A tobe cut off for forming connective conductor structures 104 havingdifferent connection patterns can be computer controlled, and therefore,there is no need to replace a die of the press machine, and thiseliminates the time loss or erroneous operations which may result fromthe die replacement work, and thus contributes to improvement in theproduction efficiency and reduction in the manufacturing cost. Further,because no printed circuit boards are used in forming the light sourceassembly 101, it is possible to eliminate solder which is usually usedfor connection with the printed circuit board. This not only reducesundesirable affects on environment but also eliminates undesirableeffects of heat generated when using the solder on the light sources(LEDs). The light source assembly is of quite a simple structureconstituted by the light sources (LEDs) and the connective conductorstructure, and thus can be disassembled easily and, in combination withno use of the printed circuit board which typically is hard to recycle,can be recycled efficiently.

FIG. 22 is a partial perspective view showing another embodiment of alight source assembly according to the present invention. A light sourceassembly 151 shown in FIG. 22 uses normal-view chip-type LEDs (orsurface mount type LEDs) 152 each of which has, instead of the leadwires 103, a pair of electric connection terminals 153 extending fromits side to bottom and has a light emitting portion 152A on its top.Commercially available chip-type LEDs comprise quite small ones havinglongitudinal, lateral and height dimensions each less than fewmillimeters, and therefore, the light source assembly 151 using suchLEDs can have a small size.

In a similar manner as in the embodiment shown before, the LEDs 152 areelectrically connected by a connective conductor structure 154 formed bycarrying out secondary processing of a substantially plate-likepatterned conductor 170 (see FIG. 25). Also similarly, the connectiveconductor structure 154 comprises first and second trunk paths 161, 162extending in the longitudinal direction and applied with power supplyvoltage, and arranged between the pair of trunk paths 161, 162 is aninterconnection path 160 for longitudinally connecting light sourceattachment portions 155 (see FIG. 25) for connection with the LEDs 152.The first and second trunk paths 161, 162 are electrically connected tothe interconnection paths 160 at predetermined positions by branch paths163, 164 extending in a widthwise direction, and in the shownembodiment, form a conductor pattern connecting the LEDs 152 in aseries-parallel connection. In a similar manner as in the embodiment ofFIG. 16, the second trunk path 162 is formed with pilot holes 168 forfacilitating handling in the progressive press machine. Further, theinterconnection path 160 and the first and second trunk paths 161, 162are mechanically joined by widthwise-extending insulating joint members165, which are formed by insert molding.

In this embodiment, substantially box-shaped sockets 172 each having anopening in its top for receiving an associated chip-type LED 152 areformed at positions aligned with the light source attachment portions155 of the connective conductor structure 154. Such a socket 172 can bepreferably formed by insert molding.

FIG. 23 is a top view showing the socket 172 without the LED 152 fittedtherein (the one second to the left in FIG. 22), and FIG. 24 is a sidecross-sectional view showing the socket 172 fitted with the LED 152(left end one in FIG. 22, for example). As seen in these drawings, eachof the light source attachment portions 155 of the connective conductorstructure 154 has a pair of longitudinally spaced terminal connectionparts 159, which are positioned over a bottom wall of the associatedsocket 172 and exposed-so that upon insertion of the LED 152 into thesocket 172, the terminals of the LED 152 and the terminal connectionparts 159 of the connective conductor structure 154 contact each other.In order to ensure the contact between the terminals 153 of the LED 152and the terminal connection parts 159, a small projection 167 isprovided on a surface of each terminal connection part 159. The bottomwall of each socket 172 is formed with a hole 173, making it possible topush the LED 152 in the socket 172 through the hole 173 to therebyremove the LED 152 from the socket 172. This can facilitate replacementof a malfunctioning LED 152 with a normal one.

As in the embodiment of FIG. 16, the connective conductor structure 154in the embodiment shown in FIGS. 22-24 also can be preferably formed bycutting off parts of a plate-shaped patterned conductor as required in asecondary processing thereof, where the patterned conductor has aprescribed circuit pattern. FIG. 25 is a plan view showing a patternedconductor 170 suitable for use in the embodiment of FIGS. 22-24 in astate before being applied with the secondary processing. In thisdrawing, parts corresponding to those shown in FIGS. 22-24 are denotedwith same reference numerals.

Like the patterned conductor 120 shown in FIG. 18, this patternedconductor 170 is also has a longitudinal tape-like shape, in which theinterconnection path 160 extends longitudinally to connect the lightsource attachment portions 155 in the longitudinal direction. The firstand second trunk paths 161, 162 are disposed on either side of thepatterned conductor 170 so as to interpose the interconnection path 160and the light source attachment portions 155 therebetween. Each terminalconnection part 159 of each light source attachment portion 155 isconnected to the first and second trunk paths 111, 112 via associatedbranch paths 163, 164. The interconnection path 160 comprises aplurality of connection paths 171 each coupling a pair of terminalconnection parts 159 that are to engage lead wires 153 of adjoining,different LEDs 152 (i.e., that are contained in adjoining light sourceattachment portions 155). The joint members 165 formed by insert moldingcan be disposed on a longitudinally middle portion of the associatedconnection paths 171 (see FIG. 22). In forming the joint members 165, aportion of each joint member 165 aligned with the associated connectionpath 171 is formed with a hole 169 to expose the connection path 171 (apart of the connection path 171 exposed by the hole 169 is referred toas a bridge portion 171A). In this way, after the joint members 165 areformed, a punch of a press machine (not shown) can be inserted into thehole 169 to cut off the bridge portion 171A to whereby separate theterminal connection parts 159 that were connected by the connection path171. In this embodiment, each bridge portion 171A exposed by theassociated hole 169 of the joint member 165 is formed with a relativelynarrow width to ensure the exposure of the bridge portion 171A by thehole 169 and to facilitate cutting off of the same. It should be notedthat the bridge portion 171A may have an arbitrary shape, and maycomprise two narrow paths crossing each other, for example. Further, inorder to facilitate cutting, it is possible to form perforations inappropriate portions of the connection path 171

In this embodiment, longitudinally extending tongue pieces 174 areformed by making a cut in portions of the connection paths 171 adjacentto the terminal connection parts 159 of the light source attachmentportions 155. As shown in the perspective view of FIG. 22 and in thecross-sectional view of FIG. 24, in the assembled state, the tonguepieces 174 are raised to stand upright and bent to press the top of theLEDs 152 received in the sockets 172 so as to prevent inadvertentremoval of the LEDs 152 from the sockets 172.

FIGS. 26-28 show ways of secondary processing of the patterned conductor170 for forming the connective conductor structure 154 adapted forseries-parallel, series, and parallel connections, respectively. As inFIGS. 19-21, parts to be cut off are shown by hatching. Further, inorder to help understand the positions to be cut off, the joint members165 and the sockets 172 are shown in broken lines. Since FIGS. 26-28 aresubstantially the same as FIGS. 19-21, detailed explanation thereof isomitted, but it will be understood from the drawings that connectiveconductor structures 154 having various connection patterns can beformed from the patterned conductor 170.

FIG. 29 is a partial perspective view showing an embodiment modifiedfrom that of FIG. 22. In FIG. 29, parts similar to those in FIG. 22 aredenoted with same reference numerals and detailed description thereof isomitted. This light source assembly 151′ is different from theembodiment shown in FIG. 22 in that so-called side-view LEDs 152′ whichhave a light emitting portion on a side surface are used as lightsources in the light source assembly 151′. Sockets 172′ for receivingthe LEDs 152′ have a side wall, part of which is cut away to form anopening 176 so as not to block the light emitted from the LED 152′. Isshould be noted that both lateral side walls of each of the sockets 172′may be provided with an opening so that the LEDs 152′ can be situated toface different ways to emit light in both lateral directions.

FIG. 30 is a partial perspective view showing another embodimentmodified from that of FIG. 22. In FIG. 30, parts similar to those inFIGS. 22, 29 are denoted with same reference numerals and detaileddescription thereof is omitted. This light source assembly 151″ isdifferent from the embodiment shown in FIG. 22 in that the light sourceassembly 151″ comprises sockets 172″ each extending over a whole widthof the connective conductor structure 154 so as to function as jointmembers as well. This can reduce the number of parts formed by insertmolding to thereby lower the manufacturing cost. Further, in a similarfashion to the embodiment of FIG. 29, part of side walls of each socket172″ is cut away to form an opening 176 so that the side-view LED 152′may be used as a light source. Since the opening 176 is provided on bothlateral sides of each socket 172″, the LEDs 152′ can be disposed to faceopposite direction from that shown in FIG. 30. It is of course possibleto use the normal-view LEDs 152 as light sources.

FIG. 31 is a partial perspective view showing yet another embodimentmodified from that of FIG. 22. In FIG. 31, parts similar to those inFIGS. 22 are denoted with same reference numerals and detaileddescription thereof is omitted. Each terminal connection part 159′ ofeach light source attachment portion 155′ of a connective conductorstructure 154′ of this light source assembly 151 a is formed with a pairof lateral extensions 175. These lateral extensions 175 are bent by apress machine so as to form opposing walls substantially perpendicularto a primary surface of the connective conductor structure 154′ to holdthe chip-type LED 152 therebetween to whereby achieve mounting of theLED 152 to the connective conductor structure 154′. This can eliminatethe need for the sockets 172 of FIG. 22 formed by insert molding, andthus can accordingly reduce the manufacturing cost and time. In asimilar manner as in the embodiments of FIG. 22, it will be preferablethat the chip-type LEDs 152 electrically connected to the terminalconnection parts 159′ of the light source attachment portions 155′ ofthe connective conductor structure 154′ are pressed from above by thetongue pieces 174, which are formed by making a longitudinal cut inportions of the connection paths 172 adjacent the connection parts 159′and are raised to stand upright and bent, to thereby prevent inadvertentdrop of the LEDs 152.

Further, in the embodiment of FIG. 31, no LED 152 is attached to thepair of terminal connection parts 159′ of the second to the right lightsource attachment portion 155′, and the pair of terminal connectionparts 159′ are connected to each other by a bridge portion 159A tothereby connect the second to left LED 152 and the right end LED 152 inseries. As described in detail below with reference to FIG. 32, this canbe achieved by forming the bridge portions 159A, during a primaryprocessing for conducting press work to make a tape-shaped patternedconductor 170′, from which the connective conductor structure 154′ ismade, such that the bridge portions 159A connect the terminal connectionparts 159′ in respective pairs, and then in a secondary processing,cutting off only the bridge portions 159A in the light source attachmentportions 155′ to which the LEDs 152 are attached while retaining thebridge portions 159A of the light source attachment portions 155′ towhich no LEDs are attached. In this way, it is possible to adjust adistance between adjacent LEDs 152 in the completed light sourceassembly 151 a. It should be noted that although in the embodiment ofFIG. 31 the LEDs 152 are all mounted on the same side of the connectiveconductor structure 154′ (on the upper side in the drawing), it is alsopossible to attach the LEDs 152 on the other side (under side in thedrawing) by bending the extensions 175 and tongue pieces 174 in theopposite direction.

In the embodiment of FIG. 31, chip-type resistors (or surface mount typeresistors) 156 are connected between the interconnection path 160 andthe second trunk path 162. To achieve this, the connective conductorstructure 154′ is formed with a pair of resistor terminal connectionparts 178 at portions of the interconnection path 160 and the secondtrunk path 162 where the resistors 156 are mounted such that the pair ofresistor terminal connection parts 178 extend from the interconnectionpath 160 and the trunk path 162, respectively, toward each other. Thus,the pair of resistor terminal connection parts 178 form a resistorattachment portion 177. Similarly to the (light source) terminalconnection parts 159′, each resistor terminal connection part 178 has apair of extensions 179 which are bent by the press machine to formopposing walls. The chip-type resistor 156 is fitted between theopposing walls 179, and a pair of terminals 157 of the chip-typeresistor 156 are bonded to the resistor terminal connection parts 178 bylaser welding or the like. The laser welding can be preferably carriedout by irradiating a laser beam onto a point or points on a side of theresistor terminal connection parts 178 opposite to that on which theresistor 156 is mounted, but it may also possible to irradiate the laserbeam on the side on which the resistor 156 is mounted. The welding canprevent inadvertent removal of the chip-type resistor 156 from theconnective conductor structure 154′. It is preferred that the connectiveconductor structure 154′ is made of aluminum in view of achieving thelaser welding reliably. It may be further preferable if the connectingstructure 154′ is plated with tin. Arc welding, supersonic welding orspot welding (resistance welding) may also be used. However, because theterminals 157 of the chip-type resistor 156 are typically very thin andcan be easily damaged by heat, laser welding is preferred in view ofminimizing possibility of such damage. Further, it may be possible touse an electroconductive adhesive such as that containing aluminumnitride powders, for example, although in view of mechanical strength,laser welding is generally preferred. By allowing the resistors 156 tobe connected between the interconnection path 160 and the second trunkpath 162, it is possible to connect the resistors 156 and LEDs 152 inseries so as to prevent an excessive voltage from being applied to theLEDs 152.

Further, in the embodiment of FIG. 31, the joint members 165′, which areformed by insert molding so as to extend in the widthwise direction ofthe connective conductor structure 154′ for joining together theinterconnection path 160 and the pair of trunk paths 161, 162, have alength equal to the width of the connective conductor structure 154′.This can be achieved by forming a widthwise recess 166A or through-hole166B in portions of the pair of trunk paths 161, 162 as shown in FIG. 32later, so as to allow part of the insert-molded joint members 165′ toextend vertically through the widthwise recess 166A or through hole166B, whereby the joint members 165′ can securely engage with the trunkpaths 161, 162 and thus are prevented from sliding in the longitudinaldirection.

FIG. 32 is a plan view of a patterned conductor 170′ used to form thelight source assembly 151 a of FIG. 31. In this drawing, parts similarto those in FIG. 25 are denoted with same reference numerals anddetailed explanation thereof is omitted. As shown in the drawing, thepatterned conductor 170′ comprises a plurality of light sourceattachment portions 155′ for mounting the chip-type LEDs 152, and eachlight source attachment portion 155′ has a pair of terminal connectionparts 159′ corresponding to a pair of electric connection terminals 153of the chip-type LED 152. Each terminal connection part 159′ has a pairof oppositely extending widthwise extensions 175, which are bent in thesecondary processing (press work) of the patterned conductor 170′ forproviding the connective conductor structure 154′, to form the walls forholding or positioning the chip-type LED 152 as shown in FIG. 31. Inorder to facilitate the bending, a notch (groove) may be formed at abase portion of each extension 175.

In the patterned conductor 170′ of FIG. 32, as described above inconnection with FIG. 31, the pair of terminal connection parts 159′ ofeach light source attachment portion 155′ are coupled by the associatedbridge portion 159A so that only the bridge portions 159A of theattachment portions 155′ to which the LEDs 152 are mounted can be cutoff in the secondary processing of the patterned conductor 170′ forforming the connective conductor structure 154′. In the patternedconductor 170′, some of the branch paths 164 connecting theinterconnection path 1 60 to the second trunk path 162 are replaced bythe resistor attachment portions 177 for attaching the chip-typeresistor 156. Each resistor attachment portion 177 comprises a pair ofresistor terminal connection parts 178 corresponding to the pair ofelectric connection terminals 157 of the chip-type resistor 156, and thepair of resistor terminal connection parts 178 are coupled to each otherby an associated bridge portion 178A before the secondary processing ofthe patterned conductor 170′, so that the bridge portion 178A is cut offin the secondary processing only when the resistor 156 is attachedthereto. Thus, when the resistor 156 is not attached and the bridgeportion 178A is retained, the resistor attachment portion function 177functions as a conductor just connecting the interconnection path 160and the second trunk path 162. Although some of the branch paths 164 arereplaced by the resistor attachment portions 177 in the embodiment ofFIG. 32, all of the branch paths 164 may be replaced by the resistorattachment portions 177. Further, although in the embodiment shown FIGS.31, 32, the resistor attachment portions 177 for mounting the resistors156 are provided between the interconnection path 160 and the secondtrunk path 162, they may be provided between the interconnection path160 and the first trunk path 161.

As mentioned before, in the patterned conductor 170′ of FIG. 32, thefirst trunk path 161 is formed with a semi-circular widthwise recesses166A and the second trunk path 162 is formed with through-holes 166B atpositions where the joint members 165′ are to be formed. In this way,part of the insert-molded joint members 165′ extend through thewidthwise recess 166A and the through holes 166B to allow the jointmembers 165′ to be securely engaged with the trunk paths 161, 162 evenwhen the joint members 165′ have a length same as or shorter than thewidth of the patterned conductor 170′. In FIG. 32, the relatively narrowfirst trunk path 161 is formed with the widthwise recess while therelatively wide second trunk path 162 is formed with through-holes, butof course, the opposite is also possible. It is only required that partof each joint member 165′ can extend through the trunk paths 161, 162 inthe up-down direction. The widthwise recess 166A and the through holes166B may be of any shape and are not limited to the semi-circular orcircular shape.

FIG. 33 is a partial plan view showing an embodiment of the patternedconductor modified from that of FIG. 18 so as to be suitable for forminga series connection of LEDs. In this drawing, parts similar to those ofFIG. 18 are denoted with same reference numerals and detaileddescription thereof is omitted. As shown in the drawing, the patternedconductor 120′ is not equipped with the first trunk path 111 and thebranch paths 113 for connecting the first trunk path 111 to theinterconnection path 110, and hence has a smaller width. In this way, anamount of material not used in the finished light source assembly can bereduced to lower the manufacturing cost. The patterned conductor 120′ isidentical to the patterned conductor 120 of FIG. 18 except for theabsence of the trunk path 111 and branch paths 113, and therefore can beprocessed with the same progressive press machine as used for processingthe patterned conductor 120 of FIG. 18.

FIG. 34 is a partial plan view showing an embodiment of the patternedconductor modified from that of FIG. 25 so as to be suitable for forminga series connection of LEDs. In this drawing, parts similar to those ofFIG. 25 are denoted with same reference numerals and detaileddescription thereof is omitted. In a similar fashion as in the patternedconductor 120′ shown in FIG. 33, this patterned conductor 170″ is alsonot equipped with the first trunk path 161 and the branch paths 163, towhereby reduce the necessary amount of material and the manufacturingcost.

FIG. 35 is a partial perspective view similar to FIG. 16 and showsanother embodiment of the joint members. In this drawing, parts similarto those of FIG. 16 are denoted with same reference numerals anddetailed description thereof is omitted. In this light source assembly101′, a plurality of insulating sheets extending in the widthwisedirection of the connective conductor structure 104 (or patternedconductor 120) and made of vinyl chloride, for example, are used as thejoint member for joining the trunk paths 111, 112 and theinterconnection path 110. The insulating sheets 184 can be attached tothe patterned conductor 120 comprising the trunk paths 111, 112 and theinterconnection path 110 before the secondary processing thereof. Suchattachment can be preferably achieved by using adhesive, but othersuitable means such as hot melt bonding, UV curing of resin may be used.The use of sheets 184 can achieve a smaller or thinner light sourceassembly though the mechanical strength may decrease. The insulatingsheets 184 can be punched out by the press machine together with thepatterned conductor 120 in the secondary processing of the patternedconductor 120.

FIG. 36 is a partial perspective view similar to FIG. 16 and shows yetanother embodiment of the joint members, and FIG. 37 is an undersideview thereof. In these drawing, parts similar to those of FIG. 16 aredenoted with same reference numerals and detailed description thereof isomitted. In this light source assembly 101″, an insulating sheet 184′extending in the widthwise direction of the connective conductorstructure 104 (or patterned conductor 120) as well as extending in thelongitudinal direction for a predetermined length and made of vinylchloride, for example, is used as the joint member for joining the trunkpaths 111, 112 and the interconnection path 110. The insulating sheet184′ may extend a whole length of the patterned conductor 120. Such aninsulating sheet 184′ also can be attached to the patterned conductor120 by suitable means such as adhesive before the secondary processingof the patterned conductor 120. Further, it may be possible to makeholes in predetermined portions of the insulating sheet 184′ (e.g.,portions aligned with the pilot holes 118 or portions for receiving thelead wires 103 of the LEDs 102). As best shown in the underside view ofFIG. 37, in the present invention, openings 185 are provided so as toexpose the terminal connection parts 109 (i.e., light source attachmentportions 105) of the connective conductor structure 104, wherebyallowing the laser beam for laser welding can impinge on the exposedparts from underside. Like the embodiment of FIG. 35 that uses theplurality of insulating sheets 184, the embodiment of FIG. 36 can alsoachieve a smaller or thinner light source assembly compared with thosethat utilize insert molding. Further, compared with the plurality ofinsulating sheets 184, the insulating sheet 184′ of FIG. 36 can beattached to the patterned conductor 120 more easily and with shortertime. In FIG. 36, the insulating sheet 184′ extends the whole width ofthe connective conductor structure 104. However, the insulating sheet184′ only has to join the trunk paths 111, 112 and the interconnectionpath 110, and thus does not have to extend the whole width. For example,it may have such a width as not closing the pilot holes 118.

The light source assembly 101″ that uses the insulating sheet 184′ asthe joint member as shown in FIG. 36 can be easily attached to a mountboard (holder) 180 formed with grooves 181, 182 by bending the branchpaths 113, 114 so that the trunk paths 111, 112 are perpendicular to aprincipal surface of the interconnection path 110, and then insertingthe trunk paths 111, 112 into the associated grooves 181, 182 as shownin FIG. 38. The mount board 180 may be formed with a groove or hole forreceiving the parts projecting on the underside of the light sourceassembly 101″ such as the lead wires 103 of the LEDs 102. The mountboard 180 may be formed by molding so as to be unitary to the lightsource assembly 101. Further, it may be possible to arrange a pluralityof light source assemblies 101″ in the widthwise direction to form atwo-dimensional light source. In such a case, it is preferable that thelongitudinal and lateral pitches of the LEDs 102 are adjusted to beidentical. In the light source assembly 101 shown FIG. 16, the trunkpaths 111, 112 and interconnection path 110 of the connective conductorstructure 104 are joined together by the joint member 115 formed byinsert molding. However, after the LEDs 102 have been attached to theconnective conductor structure 104, the trunk paths 111, 112 andinterconnection path 110 are held unitarily by the LEDs 102 and thebranch paths 113, 114, and therefore, the joint members 115 can beremoved. In such a case also, the light source assembly 101 can beattached to the mount board in a similar manner as shown in FIG. 38.This also applies to the light source assembly shown in FIG. 22.

FIG. 39 is a perspective view showing an embodiment 190 of a lightemitting apparatus using the light source assembly 101″ that uses theinsulating sheet 184′ as the joint member as shown in FIG. 36, FIG. 40is a lateral cross-sectional view thereof taken along the lines XL-XL,and FIG. 41 is a schematic top view thereof. In these drawings, partssimilar to those of FIG. 36 are denoted with same reference numerals anddetailed description thereof is omitted. As best seen in FIG. 41, inthis embodiment, each of N number of LED series connections L₁-L_(N)included in the light source assembly 101″ comprises four LEDs 102 and achip-type resistor 156 (see FIG. 31) connected in series with the LEDs102. The attachment of the chip-type resistor 156 can be achieve bycutting off a part of the interconnection path 110 (or connection path121) between adjoining LEDs 102, placing the chip-type resistor 156across the cut off portion, and then laser welding the terminals of theresistor 156 to the connection paths 121. Of course, the number of LEDs102 contained in each LED series connection L₁-L_(N) may be variedarbitrarily.

The light emitting apparatus 190 shown in the drawings comprises alight-transmissive tubular member 191 having a cylindrical shape andfunctioning as a housing for accommodating the light source assembly101″ therein. When the LEDs 102 having a sufficiently small size areused, the tubular member 191 can have a small diameter such as 0.5-2 cm.The light-transmissive tubular member 191 can be made of a plasticmaterial, but in view of efficient heat dissipation, it is preferredthat the tubular member 191 consists of a glass tube, which has afavorable heat conductivity.

Each end of the tubular member 191 is fitted with a cap member 192holding a pair of conductive pins 193. One of the pair of conductivepins 193 on each end of the tubular member 191 is connected to the firsttrunk path 111 of the light source assembly 101″, while the other isconnected to the second trunk path 112. In this way, by connecting apair of conductive pins 193 provided on one end of the tubular member191 to the power supply, the power supply voltage can be provided to theLEDs of the light source assembly 101″ via the trunk paths 111, 112.

Thus, in this embodiment, the trunk paths 111, 112 of the light sourceassembly 101″ can be used as wirings (or electric paths) for connectingthe LEDs 102 to the power supply. This can significantly improve theefficiency in assembling process compared with a case where additionalwirings are needed. Further, the light emitting apparatus can beconnected to another light emitting apparatus 190 via associatedconductive pins 193, and by repeating it, it is possible to connect anarbitrary number of light emitting apparatuses 190. In such a case, forthe purpose of easy connection, it is possible that the conductive pines193 on one end are of male-type while the conductive pines 193 on theother are of female-type. It is also possible to use a connector cablespecifically designed for such connection. It should be noted that if itis intended to use the apparatus 190 stand-alone, the first and secondtrunk paths 111, 112 of the light source assembly 151 may be connectedonly to the conductive pins 193 on one end of the tubular member 191.

In the light emitting apparatus 190 shown in FIGS. 39-41, heat isgenerated from the resistors 122 or LEDs 102 in an operating state.Further, because the ends of the tubular member 191 are sealed by thecap members 192, little heat convection will be caused if the tubularmember 191 has a small diameter such as 0.5-2 cm. Thus, if a printedcircuit board with a circuit-forming copper film of about 35 μm and thuswith a poor heat conductivity (or low heat conduction rate) were used,the heat generated from the elements such as the resistors 122 and LEDs152 would be trapped around the surfaces of the elements, causing arapid increase in temperature of the atmosphere around the elements.This could cause damage to the elements or lower the performancethereof. However, the light emitting apparatus 190 shown in FIGS. 39-41uses the light source assembly 101″ comprising the connective conductorstructure 104 (FIG. 38) that can be formed from a conductive platematerial through (primary and secondary) press working, and the typicalthickness of the plate material can be about 0.1-0.3 mm, which isconsiderably larger than the thickness of the copper film of the printedcircuit board. Thus, the heat conducting property can be much improvedcompared with the printed circuit board, and the heat generated from theelements can be quickly dissipated. This can prevent excessivetemperature increase around the elements, and achieve substantially eventemperature distribution within the tubular member 191.

Moreover, the first and second trunk paths 111, 112 are attached with aplurality of elastic, arcuate heat transmission plates 194 by such meansas welding or screws, where the heat transmission plates 194 arepreferably formed of metal such as aluminum and serve as heattransmission members. The heat transmission plates 194 also function assupport members for supporting the light source assembly 101″ in thetubular member 191. As shown in the cross-sectional view, the heattransmittance plates 194 each have a cross-sectional shape extendingalong the inner surface of the tubular member 191 and pressedly contactthe tubular member 191. This can allow the heat to be transmitted fromthe first and second trunk paths 111, 112 to the glass tubular member191 via the heat transmission plates 194, and then to be dissipated fromthe tubular member 191 to the outside, whereby suppressing thetemperature increase within the tubular member 191. In other words, theuse of heat transmission plates 194 allows the tubular member 191 tofunction as a heat sink. Besides the case where the glass tubular member191 is used, when the light source assembly 101″ is accommodated in ahousing made of a material having a favorable heat conductive andelectrically insulating properties such as ceramic, the above describedheat transmission plates can be similarly used to transmit the heat tothe housing and dissipate heat to the outside via the housing. It shouldbe noted that though in the shown embodiment the used heat transmissionplates 194 are each relatively small, it may be possible to use the heattransmission plates 194 having substantially the same length as thetubular member 191. Further, the shape of the housing may not be limitedto the tubular shape, and the shape of heat transmission plates 194 alsocan vary depending on the shape of the housing. It will be alsopreferred if all or part of the upper surface and/or undersurface of thelight source assembly 101″ is colored in black, because this can allowheat to be radiated as infrared light. The coloring can be achieved byapplying black nickel plating, black chrome plating or chromatetreatment, or using black anodized aluminum as a material.

In the above embodiments, each light source consists of a single lightemitting element such as the bullet-type LED 102 having a pair of leadwires or the chip-type LED 152 without the lead wires. However, a singlelight source may consist of a light emitting element assembly comprisinga plurality of light emitting elements as shown in the followingembodiments.

FIG. 42 a is a perspective view for explaining an embodiment using alight emitting element assembly 195 as a light source. In thisembodiment, the tape-shaped patterned conductor 120 applied with thesecondary processing shown in FIG. 20 for achieving parallel connectionof the light sources can be used as the connective conductor structure104. In FIG. 42 a, parts similar to those of the above embodiment aredenoted with same reference numerals and detailed description thereof isomitted. It should be noted that when the circuit for parallelconnection is formed, the pair of terminal connection parts 109 of eachlight source attachment portion 105 of the connective conductorstructure 104 are connected to the trunk path 111 or 112 via anassociated branch path 113 or 114, and therefore, the insert-moldedjoint members 115 for preventing the parts of the connective conductorstructure 104 from being separated apart are unnecessary.

In the embodiment of FIG. 42 a, the light emitting element assembly 195comprises six chip-type LEDs 196 and a chip-type resistor 197 arrangedin a line and electrically connected on a support member 198 which mayconsist of a printed circuit board, for example. Further, the lightemitting element assembly 195 has a pair of lead wires or conductivepins 199 mutually spaced apart a distance corresponding to that betweenthe pair of terminal connection parts 109 of each light sourceattachment portion 105 of the connective conductor structure 104 andextending downwardly to serve as terminals for electrical connection.The LEDs 196 and resistor 197 of the light emitting element assembly 195can be series-connected, for example, as shown in the circuit diagram ofFIG. 42 b. In this way, in a similar fashion as explained with respectto the embodiment of FIG. 16, the light emitting element assembly 195 asa light source can be connected to the connective conductor structure104 by inserting the lead wires 199 into the connection holes 116 formedin the terminal connection parts 109. By enabling the light emittingelement assembly 195 to be mounted to the connective conductor structure104 as a light source, it is possible to provide a wider variety ofillumination effects. For example, as shown in FIG. 42 a, it is possibleto use a plurality of light emitting element assemblies 195 as lightsources such that adjacent assemblies 195 contact each other in thelongitudinal direction, to thereby achieve an even, smooth illuminationwithout dark portions between the light sources. Instead of using aprinted circuit board as the support member 198 for forming the lightemitting element assembly 195, it may be possible to embody the lightemitting element assembly 195 by using the light source assemblies 151,151′ shown in FIGS. 22 and 31, for example.

FIGS. 43 a and 43 b show an embodiment using another example of lightemitting element assembly. FIG. 43 a is a perspective view forexplaining an embodiment of light source assembly using such a lightemitting element assembly 195′ as a light source, and FIG. 43 b is acircuit diagram of the light emitting element assembly 195′. In FIGS. 43a and 43 b, parts similar to those of FIGS. 42 a and 42 b are denotedwith same reference numerals and detailed description thereof isomitted. In the light emitting element assembly 195′, five seriesconnections, each of which comprises six LEDs 196 and a resistor 197connected in series, are juxtaposed on a support member 198′ having aprinted circuit board, for example, to achieve two-dimensional lightemission. In this embodiment also, in a similar fashion as in theembodiment shown in FIG. 42, a pair of lead wires or conductive pins 199are provided on a side of the support member 198′ opposite to that onwhich the LEDs 196 and resistors 197 are mounted such that the leadwires 199 are spaced apart a prescribed distance from each other andextend substantially in parallel to function as electrical connectionterminals for connection to the terminal connection parts 109 of theconnective conductor structure 104. As shown in the drawings, the lightemitting element assembly 195′ may have a same width as the connectiveconductor structure 104. In this way, when a plurality of such lightsource assemblies using the light emitting element assembly 195′ arejuxtaposed in the widthwise direction, the space between adjacent lightsource assemblies can be properly adjusted to achieve even illuminationover the whole surface. Further, the light emitting element assemblies195′ are preferably arranged without space in the longitudinal directionto eliminate dark portions between the light sources. It should be notedthat the light emitting element assembly 195′ is not limited to squareor rectangular shapes, but may take an arbitrary shape such as acircular shape. Also, though the tape-shaped patterned conductor 120applied with the secondary processing for forming a parallel connectionof light sources was used as the connective conductor structure 104 inthe above embodiments, it is of course possible to use the patternedconductor applied with the secondary processing for achieving otherconnections such as series-parallel connection or series connection(FIGS. 19, 21) by suitably choosing the connection pattern of the lightemitting elements and/or a value of resistance of the resistors in thelight emitting element assembly.

The light source assembly 151 a using the chip-type LEDs 152 as lightsources as shown in FIG. 31 can be flexed in the longitudinal directionbecause the connective conductor structure 154′ is substantiallyplate-like and has a flexibility. In the embodiment of FIG. 31, however,the pair of electric connection terminals 153 of each chip-type LED 152(and the associated pair of terminal connection parts 159′ of theconnective conductor structure 154′) are spaced apart in thelongitudinal direction, and therefore, when the light source assembly151 a is flexed, a force may act upon the terminal connection parts 159′of the connective conductor structure 154′ and the terminals 153 of theLED 152 to urge them away from each other. Even though the tongue pieces174 press the LEDs 152 from above in the embodiment of FIG. 31, it isnot favorable that electrically contacting parts (i.e., terminals 153and terminal connection parts 159′) are subjected to a force that urgesthem away from each other in view of preventing false electric contact.It may be conceived to laser-weld the LEDs 152 to the connectiveconductor structure 154′, but in such case also, a force urging theelectrically contacting parts away from each other should be avoided.

FIG. 44 shows an embodiment of a tape-shaped patterned conductor adaptedto solve such problems. As shown in the drawing, this patternedconductor 200 can be formed by press working so as to have a prescribedpattern in a similar fashion as in the above embodiments, and, with asecondary processing for cutting off appropriate parts, can make aconnective conductor structure having a desired circuit configuration.Specifically, the patterned conductor 200 comprises first and secondtrunk paths 211, 212 extending substantially in parallel in alongitudinal direction, a plurality of light source attachment portions215 arranged in the longitudinal direction between the first and secondtrunk paths 211, 212 for electrical connection with chip-type LEDs 202(see FIG. 45) as light sources, an interconnection path 210 forlongitudinally connecting the light source attachment portions 215, anda plurality of branch paths 213, 214 connecting the interconnection path210 and the trunk paths 211, 212 in a widthwise direction, so thatcutting off appropriate branch paths 213, 214 can realize a connectiveconductor structure for connecting the chip-type LEDs 202 in variousconnection patterns such as series, parallel or series-parallelconnection.

In the embodiment of FIG. 44, each light source attachment portion 215comprises a pair of light source terminal connection parts 216 which arespaced apart in a direction perpendicular to the longitudinal directionof the patterned conductor 200 (i.e., in the widthwise direction). Inthis way, when each chip-type LED 202 used as a light source is mountedto the associated light source attachment portion 215, the pair ofterminals 203 of the chip-type LED 202 is arranged so as to be spacedapart substantially in a direction perpendicular to the longitudinaldirection of the patterned conductor 200 (and hence of the connectiveconductor structure formed therefrom).

Each terminal connection part 216 comprises a pair of extensions 217extending out in the longitudinal direction of the patterned conductor200. Like the extensions 175 of the embodiment shown in FIG. 31, theextensions 217 are bent so as to be perpendicular to a primary surfaceof the patterned conductor 220 to form walls for holding or positioningthe LEDs 202. In the shown example, the pair of terminal connectionparts 216 of each light source attachment portion 215 are separated fromeach other, but in a similar fashion as in the embodiment shown in FIGS.31, 32, they may be connected to each other so that they can beseparated in the secondary processing of the patterned conductor 200only when the LED 202 is actually mounted thereto.

The patterned conductor 200 of FIG. 44 is further provided with aresistor attachment portion 225 between the left two light sourceattachment portions 215 for attaching a chip-type resistor 205 (see FIG.45) thereto. Like the light source attachment portions 215, the resistorattachment portion 225 comprises a pair of resistor terminal connectionparts 226 which are spaced apart from each other in the widthwisedirection of the patterned conductor 200.Each resistor terminalconnection part 226 comprises a pair of extensions 227 extending out inthe longitudinal direction of the patterned conductor 200. Like theextensions 179 of the embodiment shown in FIG. 31, the extensions 227are bent so as to be perpendicular to the primary surface of thepatterned conductor 200 to form walls for holding or positioning theresistor 205. The provision of resistor attachment portion 225 canfacilitate connection of the resistor 205 between the adjacent LEDs 202and can arrange the pair of terminals 206 of the mounted resistor 205 soas to be spaced apart in a direction substantially perpendicular to thelongitudinal direction of the patterned conductor 200. Like the lightsource attachment portions 215, it is possible to couple the pair ofresistor terminal connection parts 226 of the resistor attachmentportion 225 at the time when the patterned conductor 200 is formed, andseparate them in the secondary processing of the patterned conductor 200only when the resistor 205 is attached thereto.

Further in the patterned conductor 200 in FIG. 44, the first and secondtrunk paths 211, 212 extending in the longitudinal direction has atortuous shape. Specifically, portions of the trunk paths 211, 212longitudinally aligned with the light source attachment portions 215, towhich the LEDs 202 are mounted, curve convexly or outward in thewidthwise direction (or in a direction away from the interconnectionpath 210) to form convexly curved portions 211A, 212A. Each convexlycurved portion 211A, 212A as shown is curved substantially in a shape ofa letter “]”, but may be curved arcuately instead. In this way, it ispossible to bend the convexly curved portions 211A, 212A of the trunkpaths 211, 212 at their base so as to be substantially perpendicular tothe principal surface of the interconnection path 210 whereby the bentportions can be used in attachment to a support plate (see FIG. 45). Inthis patterned conductor 200, the trunk paths 211, 212 are relativelynarrow and therefore, a longitudinally extending side frame 219 isadditionally provided and connected to the second trunk path 212 by aplurality of joint parts 220 wherein the side frame 219 is formed withpilot holes 218 for engagement with pilot pins of a progressive pressmachine (not shown) so that the tape-shaped patterned conductor 200 canbe easily handled by the progressive press machine. The side frame 219can be separated from the second trunk path 212 by cutting off the jointparts 220 in the last step of the secondary processing of thetape-shaped patterned conductor 200 by the press machine.

FIG. 45 is a perspective view showing a light source assembly 201 usingthe patterned conductor 200 shown in FIG. 44 and a holder 230 forholding the light source assembly 201. As shown, the light sourceassembly 201 comprises a connective conductor structure 204 formed bycutting off prescribed parts of the patterned conductor 200 shown inFIG. 44 so as to achieve a desired circuit structure, to which thechip-type LEDs 202 and chip-type resistors 205 are mounted. Morespecifically, the pair of longitudinal extensions 217 of each lightsource terminal connection part 216 of the connective conductorstructure 204 are bent to form opposing walls between which anassociated chip-type LED 202 serving as a light source is inserted andattached. It will be understood that because the pair of terminalconnection parts 216 for each LED 202 are spaced apart in the widthwisedirection of the light source assembly 201, the pair of electricconnection terminals 203 of each LED 202 are also arranged along thewidthwise direction in an assembled state. This embodiment comprises notongue pieces 174 for pressing the LEDs 202 from above as shown in FIG.31, and the connection between the terminal connection parts 216 and theterminals 203 of the LEDs 202 is preferably achieved by welding such aslaser welding. Similarly, the chip-type resistors 205 are mounted to theresistor attachment portions 225 located between the light sourceattachment portions 215. The pair of longitudinal extensions 227 of eachresistor terminal connection part 226 of the resistor attachmentportions 225 are also bent to form opposing walls between which anassociated chip-type LED 202 is inserted. Similarly to the chip-typeLEDs 202, the connection between the terminals 206 of the chip-type LED202 and the terminal connection parts 226 is also achieved by weldingsuch as laser welding. It is preferred that the chip-type LEDs 202 andthe chip-type resistors 205 are mounted on the same side of theconnective conductor structure 204 because it requires the laser beam tobe irradiated only onto one side of the connective conductor structure204 and thus the manufacturing apparatus can be simplified. It should benoted that in FIG. 45, the left end LED 202 and resistor 205 are shownspaced away from the connective conductor structure 204 formed bycutting off parts of the patterned conductor 200 as required, but inpractice, it is preferable that those parts (branch paths 213, 214) ofthe patterned conductor 200 are cut off to form the connective conductorstructure after the LED 202 and the resistor 205 are welded to thepatterned conductor 200 to thereby prevent the parts of the connectiveconductor structure 204 from being disconnected from each other. As analternative way to prevent the parts of the connective conductorstructure 204 from being separate apart, the insulating sheets 184, 184′as shown in FIGS. 35, 36 may be attached to the patterned conductor 200before cutting off parts of the patterned conductor 200.

As described above, the convexly-curved portions 211A, 212A of the firstand second trunk paths 211, 212 of the tape-shaped patterned conductor200 are bent at their base so as to be perpendicular to the principalsurface of the light source assembly 201. As seen FIG. 45, the bentconvexly-curved portions 211A, 212A are tightly fitted in associatedgrooves 231 formed in a flexible holder 230, for example, so that thelight source assembly 201 is attached to the holder 230 to form a lightemitting apparatus 240.

FIG. 46 is a schematic perspective view showing a state of thethus-formed light emitting apparatus 240 flexed in the longitudinaldirection. In this drawing, the connective conductor structure 204 isomitted. As seen in FIG. 46, the pair of terminals 203 of each LED 202are arranged along the widthwise direction of the light emittingapparatus 240, and thus no force that urges the terminals 203 of theLEDs 202 in a direction away from the terminal connection parts 216 ofthe connective conductor structure 204 is generated even when the lightemitting apparatus 240 is flexed in the longitudinal direction.

FIG. 47 a is a plan view showing yet another embodiment of a tape-shapedpatterned conductor, FIG. 47 b is a cross-sectional view taken along thelines A-A in FIG. 47 a, and FIG. 47 c is a plan view of a light sourceassembly formed by attaching chip-type LEDs and chip-type resistor to aconnective conductor structure formed by cutting off parts of thepatterned conductor of FIG. 47 a as required. The patterned conductor250 shown in FIG. 47 a has a structure suitable for forming a lightsource assembly 251 (FIG. 47 c) of a series-parallel connection typeformed by connecting a plurality of series blocks in parallel, with eachseries block comprising four chip-type LEDs 252 and a chip-type resistor255 connected in series.

Similarly to the above embodiments, as shown in FIG. 47 a, thistape-shaped patterned conductor 250 comprises first and second trunkpaths 261, 262 extending substantially in parallel in a longitudinaldirection, a plurality of light source attachment portions 265 arrangedin the longitudinal direction between the first and second trunk paths261, 262 for electrical connection with chip-type LEDs 252 as lightsources, an interconnection path 260 for longitudinally connecting thelight source attachment portions 265, and a plurality of branch paths263, 264 connecting the interconnection path 260 and the trunk paths261, 262 in a widthwise direction. In this embodiment, a resistorattachment portion 275 for attachment of the chip-type resistor 255 isformed between the second to the left and third to the left light sourceattachment portions 265. Each light source attachment portion 265 has apair of terminal connection parts 266 corresponding to the pair ofterminals of the chip-type LED 252, and similarly, the resistorattachment portion 275 also has a pair of terminal connection parts 276corresponding to the pair of terminals of the resistor 255. In thisembodiment, the adjoining light source attachment portions 265 andresistor attachment portion 275 in a series block are connected by theinterconnection path 260, while the adjoining light sources 265contained in different series blocks are separated beforehand. The trunkpaths 261, 262 in this embodiment are relatively narrow and therefore, alongitudinally extending side frame 269 is provided and connected to thesecond trunk path 262 by a plurality of joint parts 270 where the sideframe 269 is formed with pilot holes 268 for engagement with pilot pinsof a progressive press machine (not shown) for progressive press work.

In this embodiment, each terminal connection part 266 of each lightsource attachment portion 265 is provided with a projection 267 forpositioning the LED 252. Similarly, each terminal connection part 276 ofeach resistor attachment portion 275 is provided with a projection 277for positioning the resistor 255. The projections 267, 277 can bepreferably formed by making a widthwise cutting in the terminalconnection parts 266, 276 at positions aligned with ends of the LEDs 252or resistors 255 to be mounted, and then, raising portions of theterminal connection parts 266, 276 on the side opposite to theLED-mounted side with respect to the cutting by using a press machine(see FIG. 47 b). The provision of such projections 267, 277 allows easypositioning of the LEDs 252 and resistors 255 on the patterned conductor250. Thereafter, subsequent to connecting the LEDs 252 and resistors 255to the patterned conductor by laser welding, for example, parts of thepatterned conductor are cut off as required to make the connectiveconductor structure 254 having a desired circuit pattern to form thelight source assembly 251 (FIG. 47 c). Alternatively, in a similarmanner as in the embodiment of FIG. 36, the insulating tape 184′ may beattached to the tape-shaped patterned conductor 250 before cutting offparts of the patterned conductor 250 as required to form the connectiveconductor structure 254 and mounting the LEDs 252 and resistors 255 tothe connective conductor structure 254. It is also possible to usewidthwise-extending joint members, such as the joint members 115 shownin FIG. 19, to prevent the parts of the connective conductor structure254 from being separated apart.

In the above embodiments, the light sources are of so-called “two-pole”type, such as the bullet type LED 102 having a pair of lead wires aselectric connection terminals, or the chip-type LEDs 152, 152′, 202, 252having a pair of terminals unitary to the main body, or the lightemitting element assembly 195, 195′ having two lead wires. These days,however, so-called “three-pole LED lamps” or “four-pole LED lamps”having three or four electric connection terminals and containing twoLED chips for emitting different color lights, for example. It will beconvenient if there is a tape-shaped patterned conductor suitable forsuch three-pole or four-pole LED lamps, and a light source assemblyobtained by combining such patterned conductor and the three-pole orfour-pole LED lamps. The following embodiments are for providing such alight source assembly using the three-pole or four-pole LED lamps.

FIG. 48 a is a front view of a typical three-pole LED lamp 302, and FIG.48 b is a circuit diagram thereof. As shown in the drawings, Thethree-pole LED lamp 302 comprises two LED chips for emitting lights ofdifferent colors such as yellow and red, and cathodes of the two LEDchips are connected to each other and can be connected to an outsidecircuit via a first lead wire 303A. An anode of one LED chip and ananode of the other LED lamp can be connected to an outside circuit viasecond and third lead wires 303B, 303C, respectively. Though in theshown embodiment the cathodes of the two LEDs are connected to eachother, the anodes may be connected to each other instead.

FIG. 49 is a partial plan view of a tape-shaped patterned conductor 300suitable for using a plurality of three-pole LED lamps 302 shown in FIG.48 as light sources to form a light source assembly. As shown, thispatterned conductor 300 has a plurality of light source attachmentportions 315 for attaching the three-pole LED lamps 402 as lightsources, where the light source attachment portions 315 are arranged inthe longitudinal direction and connected by an interconnection path 310.Specifically, each light source attachment portion 315 comprisesfirst-third terminal connection parts 316A, 316B, 316C corresponding tothe three lead wires 303A, 303B, 303C of the three-pole LED lamp andarranged in the widthwise direction, and the interconnection path 310comprises a plurality of first connection paths 321A for connecting thefirst terminal connection parts 316A of adjoining light source mountportions 315, a plurality of second connection paths 321B for connectingthe second terminal connection parts 316A of adjoining light sourcemount portions 315, and a plurality of third connection paths 321C forconnecting the third terminal connection parts 316C of adjoining lightsource mount portions 315. As also shown in the drawing, each terminalconnection part 316A, 316B, 316C is formed with a cross-shaped hole 317into which the corresponding lead wire 303A, 303B, 303C of the LED 302is inserted.

Further, on either side of the patterned conductor 300, first and secondtrunk paths 311, 312 extend in the longitudinal direction, interposingthe light source attachment portions 315 and the interconnection path310 therebetween. Via widthwise-extending branch paths 313, 314, thefirst and second trunk paths 311, 312 are connected to the second andthird connection paths 321B, 321C respectively connecting the second andthird terminal connection parts 316B, 316C, which are positioned ateither widthwise end of respective light source attachment portions 315.The second trunk path 312 is formed with pilot holes 318 for allowingeasy handling of the tape-shaped patterned conductor by a progressivepress machine (not shown).

In this embodiment, resistor attachment portions 325 for attachment ofchip-type resistors are provided between the trunk paths 311, 312 andthe terminal connection parts 316B, 316C located at widthwise ends ofrespective light source attachment portions 315. As shown, each resistorattachment portions 325 comprises a pair of resistor terminal connectionparts 326 extending from the terminal connection parts 316B, 316C andthe associated trunk paths 311, 312 toward each other. In a similarmanner as in the embodiment shown in FIG. 31, each resistor terminalconnection part 326 has a pair of opposite extensions 327 which can bebent by a press machine to form opposing walls.

A light source assembly 301 can be obtained by cutting off parts of theabove constructed patterned conductor 300 as required to form aconnective conductor structure, and mounting the three-pole LED lamps302 serving as light sources to corresponding light source attachmentportions 315 as well as mounting chip-type resistors 305 similar to theresistor 205 of FIG. 45 to the resistor attachment portions 325 (see thecircuit diagram of FIG. 51). FIG. 50 shows an example of the cutting-offpattern. In this drawing, the parts to be cut off are shown by hatching.Further, FIG. 51 shows a circuit diagram of the resulting light sourceassembly 301. As shown by broken lines in FIG. 51, a lower voltage of aDC power source is connected to the interconnection path 321A while ahigher voltage of the DC power source is connected to the first trunkpath 311 via a switch SW1 as well as to the second trunk path 312 via asecond switch SW2, such that closing the first switch SW1 can lightenthe upper LED chip in each three-pole LED lamp 302 in the drawing andclosing the second switch SW2 can lighten the lower LED chip in eachthree-pole LED lamp 302. Thus, when the upper and lower LED chips ineach three-pole LED lamp 302 have different light colors, it is possibleto vary the light color by controlling the switches SW1, SW2.

The patterned conductor 300 shown in FIG. 49 may be used to connect thebullet-type LEDs 102 having two lead wires as shown in FIG. 16 to form alight source assembly.

FIG. 52 a is an upper perspective view of a typical four-pole LED lamp,FIG. 52 b is a lower perspective view thereof, and FIG. 52 c is acircuit diagram thereof. As seen in FIGS. 52 a and 52 b, this four-poleLED lamp 402 is of a chip-type (surface mount-type) without lead wiresas terminals. The LED lamp 402 has a light emitting portion on its top.As shown in FIG. 52 c, the LED lamp 402 comprises first and second LEDchips having different light colors such as yellow and red, and has fourterminals 403 connected to associated one of anodes and cathodes of thefirst and second LED chips. Two of the terminals 403 connected to thecathodes of the first and second LED chips are provided on one end ofthe four-pole LED lamp 402, and the other two of the terminals 403connected to the anodes of the first and second LED chips are providedon the other end. In this way, the anodes and cathodes of the first andsecond LED chips contained in the four-pole LED lamp 402 can beconnected to an outside circuit via associated terminals 403.

FIG. 53 is a partial plan view of a tape-shaped patterned conductor thatcan be used in forming a light source assembly by using a plurality ofthe four-pole LED lamps 402 shown in FIGS. 52 a-52 c. As shown, thispatterned conductor 400 has a plurality of light source attachmentportions 415 for attaching the four-pole LED lamps 402 as light sources,where the light source attachment portions 415 are arranged in thelongitudinal direction and connected by an interconnection path 410.Specifically, each light source attachment portion 415 comprises fourterminal connection parts 416 corresponding to the four terminals 403 ofthe four-pole LED lamp 402, two of the terminal connection parts 416 arearranged in the longitudinal direction so as to be connected to a pairof terminals 403 for the first LED chip contained in the four-pole LEDlamp 402, while the remaining two are arranged in thelongitudinal-direction and spaced from the former two terminalconnection parts in the widthwise direction so as to be connected to apair of terminals 403 for the second LED chip contained in the four-poleLED lamp 402. The interconnection path 410 comprises a plurality offirst and second connection paths 421A, 421B for connecting the terminalconnection parts 416 contained in adjoining light source attachmentportions 415 and aligned in the widthwise direction. The firstconnection paths 421A longitudinally connect the terminal connectionparts 416 associated with the first LED chips contained in the four-poleLED lamps 402, while the second connecting paths 421B longitudinallyconnect the terminal connection parts 416 associated with the second LEDchips contained in the four-pole LED lamps 402A. Therefore, the firstconnection paths 421A and the second connection paths 421B are spacedfrom each other in the widthwise direction. The first connection paths421A and the second connection paths 421B mutually aligned in thelongitudinal direction are connected to each other in the widthwisedirection by branch paths 422.

Further, first and second trunk paths 411, 412 extend in thelongitudinal direction, interposing the light source attachment portions415 and the interconnection path 410 therebetween. Viawidthwise-extending branch paths 413, 414, the first and second trunkpaths 411, 412 are connected to the first and second connection paths421A, 421B. The second trunk path 412 is formed with pilot holes 418 forallowing easy handling of the tape-shaped patterned conductor by aprogressive press machine (not shown). Further in this embodiment, athird trunk path 419 is provided on the widthwise outer side of thefirst trunk path 411 and connected to the first trunk path 411 viabranch paths 420 extending widthwise.

A light source assembly 401 using the four-pole LED lamps 402 can beobtained by cutting off parts of the above constructed patternedconductor 400 as required to form a connective conductor structure, andmounting the four-pole LED lamps 402 serving as light sources tocorresponding light source attachment portions 415 as well as mountingresistors at prescribed positions. FIG. 54 shows an example of such acutting-off pattern. In this drawing, the parts to be cut off are shownby hatching. Further, the four-pole LED lamps 402 and chip-typeresistors 405 to be attached are shown by broken lines. FIG. 55 shows acircuit diagram of the resulting light source assembly 401. In thisembodiment, three four-pole LED lamps 402 and two resistors 405constitute a unit circuit. At one end of each unit circuit, the firstand second connection paths 421A, 421B are both connected to the firsttrunk path 411 while at the other end, one of the two resistors 405 isconnected between the first connection path 421A and the third trunkpath 419, and the other of the two resistors 405 is connected betweenthe second connection path 421B and the second trunk path 412. It shouldbe noted that the number of four-pole LED lamps 402 should not belimited to three.

As shown by broken lines in FIG. 55, a higher voltage of a DC powersource is connected to the first trunk path 411 while a lower voltage ofthe DC power source is connected to the third trunk path 419 via aswitch SW1 as well as to the second trunk path 412 via a second switchSW2, such that closing the first switch SW1 can lighten the upper LEDchip (first LED chip) in each four-pole LED lamp 402 in the drawing andclosing the second switch SW2 can lighten the lower LED chip (second LEDchip) in each four-pole LED lamp 402. Thus, when the upper and lower LEDchips in each LED 402 have different light colors, it is possible tovary the light color by controlling the switches SW1, SW2.

FIG. 56 is a partial plan view showing a yet another embodiment of atape-shaped patterned conductor according to the present invention. Thispatterned conductor 500 comprises a plurality of longitudinally arrangedlight source attachment portions 515 for mounting light sources, andthese light source attachment portions 515 are connected in thelongitudinal direction by interconnection path 510. Each light sourceattachment portion 515 includes a pair of terminal connection parts 519corresponding to a pair of terminals of a light source, and the pair ofterminal connection parts 519 are mutually spaced apart in thelongitudinal direction. Each terminal connection part 519 is formed witha cross-shaped hole 519 so that if the light source consists of abullet-type LED such as the LED 102 shown in FIG. 16, the lead wires 103thereof may be inserted into the associated cross-shaped holes 519. Ifthe light source consists of a chip-type LED such as the LED 152 asshown in FIG. 31, the LED 152 can be attached to the terminal connectionparts 519 by laser welding. The interconnection path 510 comprises aplurality of connection paths 521 connecting the terminal connectionparts 519 contained in adjoining light source attachment portions 515.In other words, a connection path 521 and a pair of terminal connectionparts 519 connected by the connection path 521 constitute a couplingpiece. Part of each connection path 521 constitutes a bridge portion521A having a relatively narrow width so as to be easily cut off toseparate the terminal connection parts 519 connected via the bridgeportion 521A. Further, first and second trunk paths 511, 512 aredisposed on either side of the patterned conductor 500, interposing thelight source attachment portions 515 and the interconnection path 510therebetween. Each light source attachment portion 515 is connected toone of the first and second trunk paths 511, 512 via corresponding oneof branch paths 513, 514 such that one of the pair of terminalconnection parts 519 of each light source mount portion 515 is connectedto the first trunk path 511 and the other is connected to the secondtrunk path 512. It is of course possible to provide the branch paths513, 524 such that each of the pair of terminal connection parts 519 isconnected to both of the first and second trunk paths 511, 512.

In this embodiment, in order to reliably attach resistors having a pairof lead wires such as the resistor 122 shown in FIG. 122, the connectionpaths 521 and second trunk path 512 are formed with cross-shaped holes523 into which the lead wires of the resistors are inserted. As shown bybroken lines in FIG. 56, a resistor 522 can be connected between theterminal connection part 519 and the second trunk path 512 or betweenadjacent terminal connection parts 519 contained in adjacent lightsource attachment portions by inserting lead wires 522A of the resistor522 into the holes 523 (and preferably laser welding them). When theresistor 522 is attached, an associated bridge portion 521A or branchpath 514 is cut off. In this embodiment, in order to allow the bridgeportions 521A and branch paths 514 to be cut off after the attachment ofthe resistors 522, the bridge portions 521A are offset from thewidthwise center of the connection paths 521, and the resistor mountholes 523 are arranged such that when the resistors 522 are attached,the resistors 522 do not overlap the bridge portions 521A or branchpaths 514.

In the connective conductor structure (FIG. 21) made by conductingsecondary processing of the tape-shaped patterned conductor 120 of FIG.18 to connect the light sources in series, for example, the branch paths113, 114 connecting the trunk paths 111, 112 to the terminal connectionparts 109 are cut off. Therefore, when the LEDs 102 (FIG. 16) areconnected by such a connective conductor structure and electric currentflows through the LEDs 102, the heat generated thereby cannot bedissipated via the trunk paths 111, 112, undesirably increasing thetemperature around the LEDs 102. FIG. 57 shows a way of secondaryprocessing of the patterned conductor 120 for achieving a seriesconnection of LEDs while allowing heat dissipation through the trunkpaths 111, 112 to prevent undesirable increase in the temperature aroundthe LEDs. In FIG. 57, parts similar to those of FIG. 18 are denoted withsame reference numerals and detailed description thereof is omitted.

As shown in FIG. 57, in this embodiment, parts of trunk paths 111, 112indicated by hatching are cut off instead of the branch paths 113, 114.In this way, it is possible to electrically separate the pair ofterminal connection parts 109, 109 in each light source attachmentportion 5 to thereby allow series connection of LEDs 102 (FIG. 16) whileretaining the trunk paths 111, 112 connected to the terminal connectionparts 109. Thus, in this embodiment, the heat generated by the currentflowing through the LEDs 102 can be dissipated from the trunk paths 111,112. This can prevent the heat from staying around the LEDs 102 andexcessively increasing the temperature. In the shown embodiment, eachterminal connection part 109 is connected to both of the first andsecond trunk paths 111, 112, it may be possible that each terminalconnection part 109 is connected to only one of the first and secondtrunk paths 111, 112.

In a case that a light source assembly is accommodated in alight-transmissive glass tube or the like to form a light emittingapparatus as in the embodiment shown in FIG. 39, if the glass tube has asmall inner diameter (about 5 mm, for example), it is required to use apatterned conductor having a narrow width accordingly. FIG. 58 a showssuch a patterned conductor 550. This patterned conductor 550 comprisesterminal connection parts 569 constituting light source attachmentportions 565 to which light source (not shown) are attached, aninterconnection path 560 for connecting the light source attachmentportions 565 in a longitudinal direction, first and second trunk paths561, 562 laterally interposing the light source attachment portions 565and interconnection path 560 therebetween and extending in thelongitudinal direction, and a plurality of widthwise extending branchpaths 563, 564 for connecting the light source attachment portions 565to the trunk paths 561, 562 in the same way as in the above embodiments,but is characterized by the trunk paths 561, 562 having a narrow width.Owing to such characteristics, the patterned conductor can beaccommodated in a glass tube having a small diameter, but it isdifficult to attach terminal pins such as the conductive pins 93 asshown in FIG. 39 for connection with outer power supply to ends of thetrunk paths 561, 562. FIG. 58 b shows an end conductor 570 to allowterminal pins to the ends of the narrow trunk paths 561, 562 of thepatterned conductor 550 shown in FIG. 58 a. This end conductor 570comprises a pair of smaller width portions 571, 572 for connection withthe trunk paths 561, 562 of the patterned conductor 550, and a pair oflarger width portions 573, 574 coupled to the smaller width portions571, 572, respectively. The pair of larger width portions 573, 574 areeach formed with a hole 573A, 574A that can be used to attach terminalpins to the larger width portions 573, 574. Preferably the end conductor570 is subjected to laser welding with the pair of smaller widthportions 571, 572 being placed over the corresponding trunk paths 561,562 so as to be unitary to the patterned conductor 550. Though in theshown embodiment the lager width portions 573, 574 are mutuallyconnected via a bridge portion 575, they are separated from each otherby cutting off the bridge portion 575 before use. Thus, by using the endconductor 570 having the pair of smaller width portions 571, 572 and thepair of larger width portions 573, 574, it becomes possible to easilyattach terminal pins to the patterned conductor 550 with the narrowtrunk paths 561, 562.

In the embodiment shown in FIG. 36, in order to prevent the parts of theconnective conductor structure 104 from being separated apart or inorder to increase the mechanical strength of the connective conductorstructure 104 to thereby allow easy handling thereof, the insulatingsheet 184′ is attached to the side of the patterned conductor 120opposite to the side on which the light sources are mounted. However, asshown in yet another embodiment 101 a of a light source assembly shownin FIG. 59, the insulating sheet 184′ may be attached by hot meltbonding or the like to the side of the patterned conductor 120(connective conductor structure 104) on which the light sources aremounted. In this drawing, parts similar to those of FIG. 36 are denotedwith same reference numerals and detailed explanation thereof isomitted. As shown, the insulating sheet 184′ is formed with openings 185at prescribed positions so that light sources (LEDs) can be attached tothe terminal connection parts 109 of the patterned conductor 120 in asimilar manner as in the embodiment of FIG. 36. Such openings 185 can beformed before the insulating sheet 184′ is attached to the patternedconductor 120 or may be formed by press work, laser processing, etc.after the attachment of the sheet 184′. By attaching the insulatingsheet 1847 to the side of the patterned conductor 120 on which the lightsources are mounted as described above, it is possible to prevent theparts to which power supply voltage are applied from being exposed onthe light source mount side which are more likely to be touched by anoperator, and thus improving the safety. Further, the insulating sheet184′ can reflex the light from the light sources 102 to increase theillumination efficiency.

In the case where the insulating sheets 184, 184′ are used, as describedabove, to prevent the parts of the connective conductor structure 104formed by secondary processing of the patterned conductor from beingseparated apart, it is preferable to attach the resulting light source101′, 101″, 101 a to a holder to add supplementary mechanical strength.In the case that the light sources 120 are attached to the patternedconductor 120 before cutting off parts of the patterned conductor 120 tomake the connective conductor structure 104 and hence a light sourceassembly, it is not necessary to use joint members such as theinsulating sheet 184′, but the mechanical strength of the resultinglight source assembly is further decreased. Therefore, in such a casealso, the use of a holder is preferred. FIG. 60 a shows a preferable wayof attachment of the light source assembly to the holder. FIG. 60 b is across-sectional view showing a state where the light source assembly hasbeen attached to the holder.

As shown in FIGS. 60 a and 60 b, this holder 580 comprises alongitudinally extending channel 582 at its center, and mutually facingside walls 583, 583 of the channel are formed with longitudinallyextending opposite guide grooves 583A, 583A corresponding to the pair oftrunk paths 111, 112 of a light source assembly 101 b. In thisembodiment, the light source assembly 101 b is formed by using thepatterned conductor 120 shown in FIG. 18 but does not comprise the jointmembers, and the cramping of the lead wires 103 by the extensions 117 isnot carried out and the lead wires 103 and the patterned conductor 120is achieved by laser processing such that the bottom surface issubstantially flat (FIG. 60 b). As seen in FIG. 60 a, by slidingly movethe light source assembly 101 b in the direction indicated by an arrowin the drawing with the pair of trunk paths 111, 112 being fitted in thecorresponding guide grooves 583A, 583A, the light source assembly 101 bcan be easily attached to the holder 580. Thereafter, as shown in FIG.60 b, a cover member 585 made of an insulating material is attached tothe side of the light source assembly 101 b on which the light sourcesare mounted, to prevent exposure of the parts applied with a powersupply voltage and avoid inadvertent short-circuit due to dust or thelike. When the insulating sheet 184′ is attached to the light sourceattachment side as shown in FIG. 59, the cover member 585 may beomitted.

FIG. 61 is a cross-sectional view showing another embodiment of aholder. The light source assemblies 101 b are each identical to thatshown in FIGS. 60 a and 60 b. This holder 590 has longitudinallyextending channels 592, 596 on upper and under sides thereof, and has across-section of a shape of the letter “H”. Mutually facing side walls593, 593 and 597, 597 of the channels 592, 596 are formed with guidegrooves 593A, 593A and 597A, 597A, respectively, into which the trunkpaths 111, 112 of the associated light source assembly are fitted. Theuse of such a holder 590 allows the light source assembly 101 b to beattached on both of the upper and under sides of the holder 590 so thatthe light can be generated on both of the upper and under sides.

The patterned conductor (120, 200, etc.) according to the presentinvention can be preferably formed by a progressive press machine asdescribed above, but it is also possible to form the patterned conductorby photo-etching. FIGS. 62 a-62 c show a preferable way of usingphoto-etching to form a patterned conductor for constituting a lightsource assembly. As shown in FIG. 62 a, a conductive plate 601 made ofphosphor bronze, for example, and an insulating plate 602 havingsubstantially the same size interposing a hot melt bonding sheet 603therebetween are pressed together at a high temperature to therebybonding the conductive plate 601 to the insulating plate 602. Then,photo-etching is conducted to form a plurality of longitudinal patternedconductors 604-1, 604-2, . . . , 604-N each having a pattern as shown inFIG. 56. In FIG. 62 b, the formed pattern is not shown. Press workingmay be conducted in addition to photo-etching to form holes forinsertion of lead wires of light sources or resistors. In this state,the patterned conductors 604-1, 604-2, . . . , 604-N are all attached tothe insulating plate 602. Subsequently, appropriate parts of patternedconductors 604-1, 604-2, . . . , 604-N are cut off by press working, forexample, to form desired connective conductor structures, on which lightsources 606 (and resistors, if necessary) are attached to make lightsource assemblies 605-1, 605-2, . . . , 605-N. It should be understoodthat in FIG. 62 c, the light source assemblies 605-1, 605-2, . . . ,605-N joined by the insulting plate 602 constitute a surface lightsource. It may be also possible to cut the insulating plate 602 after orbefore the attachment of the light sources 606 to separate the lightsource assemblies (connective conductor structures) 605-1, 605-2, . . ., 605-N from each other.

In the above embodiments, light source assemblies (101, 101′, 101″, 201,etc.) having a plurality of light sources arranged in a line by usingpatterned conductors (120, 200, etc.). However, a light source assemblycomprising a plurality of lines of light sources may be achieved byusing a patterned conductor. FIG. 63 a is a partial plan view showing anembodiment of a patterned conductor that can be used to form a lightsource assembly having, for example, two lines of light sources. Asshown in the drawing, this patterned conductor 610 has a structure thatresults from widthwise joining two patterned conductors each for forminga light source assembly having light sources arrange in a line(patterned conductors for single-line light source arrangement).Specifically, the patterned conductor 610 for two-line light sourcearrangement comprises first to third trunk paths 611, 612, 613 extendingin parallel in the longitudinal direction and used for connection withpower source, and the central second trunk path 612 is formed with pilotholes 614 for facilitating transportation/positioning of the patternedconductor in a progressive press machine. Between the first trunk path611 and the second trunk path 612, a plurality of light sourceattachment portions 615 are arranged along the longitudinal directionsuch that each light source attachment portion is connected to the firsttrunk path 611 and the second trunk path 612 by corresponding widthwiseextending branch paths 616, 617, and adjoining light source attachmentportions 615 are connected to each other by an interconnection path 618.Similarly, between the second trunk path 612 and the third trunk path613, a plurality of light source attachment portions 625 are arranged inthe longitudinal direction and connected by an interconnection path 628,and each of the light source attachment portions 625 is connected to thesecond and third trunk paths 612, 613 by corresponding widthwiseextending branch paths 626, 627. It can be said that in this embodiment,two patterned conductors, each for arranging the light sources in aline, share the central second trunk path 612. Each light sourceattachment portion 615 located between the first and second trunk paths611, 612 comprises a pair of terminal connection parts 619, 619corresponding to a pair of terminals of an associated light source, andin this embodiment, the pair of terminal connection parts 619, 619 areconnected by two bridge portions 619A, 619A which are cut off beforeattachment of the light source to separate the pair of terminalconnection parts 619, 619 in each light source attachment portion 615.Each terminal connection part 619 is formed with a hole 620 so that whena light source has a lead wire, the lead wire can be inserted into thehole 620. Similarly, each light source attachment portion 625 locatedbetween the second and third trunk paths 611, 613 comprises a pair ofterminal connection parts 629, 629 corresponding to a pair of terminalsof an associated light source, and in this embodiment, the pair ofterminal connection parts 629, 629 are connected by two bridge portions629A, 629A. Further, each terminal connection part 629 is formed with ahole 630 so that when a light source has a lead wire, the lead wire canbe inserted into the hole 630.

FIG. 63 b shows an example of secondary processing of the patternedconductor 610 of FIG. 63 a. In this drawing, light sources 635 andresistors 636 to be attached are shown by broken lines, and parts to becut off are shown by hatching. The light sources 635 and resistors 636can be of the type having lead wires such as the LEDs 102 and resistors122 shown in FIG. 16, though chip-type LEDs and resistors without leadwires also may be used. Further, electric polarities of the power supplyvoltage to be applied are shown by symbols. It should be understood thatin the shown example, the secondary processing of the patternedconductor is designed such that each line of light sources 635 form aseries-parallel connection of light sources where a plurality of seriesblocks each comprising four light source 635 are connected in parallel.Of course, the secondary processing of the patterned conductor 610 forachieving series or parallel connection of the light sources 635 in eachline of light sources may also be possible.

FIG. 64 is a plan view showing an embodiment of a patterned conductorthat can arrange light source in four lines. This patterned conductor640 has a structure resulting from widthwise joining two patternedconductors shown in FIG. 63 a, and it should be understood by applyingpower supply voltage as indicated in the drawing, each line of lightsources can receive electric power appropriately. Thus, according to thepresent invention, there is provided a patterned conductor that canarrange the light sources in a plurality of lines, and by varying theparts to be cut off in the secondary processing, can achieve variousconnections of light sources, such as parallel, series, orseries-parallel connections, in each line of light sources.

Because LEDs have a benefit that they consume little power and have longlifetime, it has been proposed using LEDs as light sources to constitutea traffic light. In the case where the LEDs are connected in series orseries-parallel connection, a single malfunctioning LED that barselectric current flow would prevent electric current from flowingthrough the other LEDs connected in series to the malfunctioning LED,and this can significantly reduce the brightness of the traffic light.Thus, it has been proposed to connect a plurality of LEDs in parallel,and to connect a plurality of thus-constituted parallel connections ofLEDs in series to form a matrix circuit (see e.g., FIG. 9 of JapaneseUtility Model Application Laid-Open No. 4-8454). In this circuit, evenwhen a single LED breaks down and stops current conduction, electriccurrent can flow through the LEDs connected in parallel with themalfunctioning LED, and thus significant decrease in the amount of lightcan be prevented. In such a circuit, however, if an LED undergoes ashort-circuiting malfunction, the ends of the LEDs connected in parallelwith the malfunctioning LED are all short-circuited so that the lightemitted from these LEDs is lost, leading to a significant decrease inthe amount of light. FIG. 65 is a schematic view showing an LED circuitsuitable for a traffic light that can prevent significant decrease inthe total amount of light even in case of such a short-circuitingfailure of an LED.

In the LED circuit 650 shown in FIG. 65, eight parallel connections 652of light sources, each of which includes five LEDs 651 connected inparallel, are connected in series to constitute a matrix circuit in thesame manner as in the conventional embodiment. The LED circuit 650 canbe characterized by that each LED 651 is connected in series with anassociated resistor 653. Owing to such a structure, even if an LED 651undergoes a short-circuiting failure, a voltage is maintained across theresistor 655 connected in series with the malfunctioning LED 651 andtherefore, short-circuit of the ends of the other LEDs connected inparallel with the malfunctioning LED 651 is prevented and the lightemission is maintained. Therefore, it is possible to prevent significantdecrease in the total amount of light, even if a single LED 651 suffersa short-circuiting malfunction. It should be noted that the number ofLEDs 651 connected in series as well as the number of light sourceparallel connections 652 connected in series can be varied arbitrarily.

As shown in FIG. 66, it is possible to form a light emitting apparatus670 by additionally preparing another LED circuit 660 in which aplurality of light source parallel connections 662 are connected inseries such that light sources 661 are connected in the matrix patternin a similar manner as in the LED circuit 650 of FIG. 65, connecting thetwo LED circuits to respective, independent power supplies (first powersupply and second power supply), and placing them such the that lightsources 651, 661 substantially overlap each other,. By using the twocircuits 650, 660 connected separate power supplies, it is possible tomaintain minimum required brightness even when one of the power suppliesfails.

As shown in FIG. 67, a light emitting apparatus 670 having a circuitstructure shown in FIG. 66 can be easily achieved by using light sourceassemblies 671 formed from patterned conductors according to the presentinvention. The light emitting apparatus 670 of FIG. 67 comprises aplurality of light source assemblies 671 arranged in the widthwisedirection, and light source assemblies 671 connected different powersupplies (first and second power supplies) are alternately placed in thewidthwise direction. The LEDs contained in each light source assembly671 are connected in parallel between a pair of trunk paths 672, 673such that each LED is connected to one trunk path 673 via an associatedresistor. Such a light source assembly can be easily formed by carryingout secondary processing of the patterned conductor 500 of FIG. 56, forexample, to cut off parts thereof as required and using it to connectthe LEDs functioning as light sources. One in every two light sourceassemblies 671 are connected by jumper wires 675, 676 to form two matrixLED circuits as shown in FIG. 65. The light source assemblies 671located at both ends are attached to the first power supply or secondpower supply. In this way, a reliable surface light emitting apparatussuitable for a traffic light can be achieved using the light sourceassemblies 671 that can be formed from the patterned conductors (500,etc.).

FIG. 68 is a schematic partial plan view showing another embodiment of alight source assembly according to the present invention, comprising aplurality of light sources spatially arranged in a line and electricallyconnected in a matrix pattern as shown in FIG. 65. In this drawing,orientations of the attached LEDs are each indicated by symbols of LEDs.This light source assembly can be also constituted by using a connectiveconductor structure made by cutting off parts of the patterned conductor500 shown in FIG. 56 as required. In this drawing, parts similar tothose shown in FIG. 56 are denoted with same reference numerals anddetailed description thereof is omitted.

In a similar manner as in the above embodiments, this light sourceassembly 700 comprises a plurality of LEDs 701 as light sourceslongitudinally arranged in a line, and in this embodiment, a pluralityof parallel connections of light source, each of which comprises threeLEDs 701 connected in parallel, are connected in series. Of course, thenumber of LEDs 701 contained in each parallel connection is not limitedto three, and other number of LEDs 701 may be included. Similarly to theabove embodiment, the light source assembly 700 has first and secondtrunk paths 511, 512 interposing the LEDs 701 therebetween and extendingin the longitudinal direction, and each of the LEDs 701 is connectedbetween the trunk paths 511, 512 via associated branch paths 513 andresistors 702. However, the light source assembly 700 is different fromthe above embodiments in a sense that in this embodiment, the directionsof LEDs 701 contained in adjoining parallel connections are opposite toeach other and parts of the first and second trunk paths 511, 512 arecut off. In this way, when a DC voltage is applied with the polarityindicated by symbols, an electric current flows generally from the leftto right in the drawing. It should be appreciated from the drawing thatbecause the directions of LEDs 701 contained in adjoining parallelconnections, cathodes of the LEDs 701 contained in an upstream one ofthe adjoining parallel connections are connected to anodes of the LEDs701 contained in a downstream one. Further, the first and second trunkpaths 511, 512 are cut at about a middle part between adjoining parallelconnections (reference numerals 703, 704) such that anodes of the LEDsof the upstream one of the adjoining parallel connections are separatedfrom cathodes of the LEDs of the downstream one and that the ends ofeach LED 701 are not short-circuited. Thus, according to thisembodiment, a linear light emitting body can be obtained in which aplurality of parallel connections, each of which comprises a pluralityof parallel connected light sources 701, are connected in series and thelight sources 701 are arranged in a line.

FIG. 69 is a schematic partial plan view showing another embodiment of alight source assembly having a similar electric circuit structure andlight source arrangement. In this light source assembly 700 a also, thepower supply voltage is applied as indicated by the symbols and electriccurrent flows generally from the left to right of the drawing. In thisembodiment, the directions of the LEDs 701 used as light sources are thesame, but in order to connect the cathodes of the LEDs 701 contained inthe upstream one of the adjoining parallel connections (or the trunkpath 512 connected to the cathodes) to the anodes of the LEDs 701contained in the downstream one (or the other trunk path 513 connectedto the anodes), two light source attachment portions 515 (or theterminal connection parts 519 contained therein) and the branch paths513, 514 connecting them to the trunk paths 511, 512 are used. As aresult, this embodiment has a drawback that the distance betweenadjoining parallel connections becomes larger than that in theembodiment shown in FIG. 68.

FIG. 70 is a partial plan view showing another embodiment of a patternedconductor suitable for constituting a light source assembly comprising aplurality of light sources spatially arranged in a line and electricallyconnected in a matrix pattern as shown in FIG. 65. A patterned conductor500 a of FIG. 70 is a modified embodiment of the patterned conductor 500shown in FIG. 56, and thus in FIG. 70, parts similar to those of FIG. 56are denoted with same reference numerals and detailed descriptionthereof is omitted. Further, FIG. 71 is a partial plan view showing alight source assembly 700 b formed by using the patterned conductor 500a shown in FIG. 70. In FIG. 71, the LEDs 701 are schematically shown sothat the orientations of the LEDs 701 are indicated. The LEDs 701 maycomprise either of the bullet-type LEDs or chip-type LEDs. In FIG. 71,parts similar to those of FIG. 68 are denoted with same referencenumerals and detailed description thereof is omitted.

The patterned conductor 500 a of FIG. 70 is different from theembodiment of FIG. 56 in that the present embodiment comprisesadditional branch paths 517, 518 at a middle part of each bridge portion521A for connecting the bridge portion 521A to the first and secondtrunk paths 511, 512. In this way, when the bridge portions 521A to belocated between adjoining light source parallel connections are cut offto make a connective conductor structure for connecting the LEDs aslight sources, the middle part of the bridge portions 521A and thebranch paths 517, 518 can be left uncut so that, as shown in FIG. 71,when the LEDs 701 are attached, cathodes of the LEDs 701 contained inthe upstream one of adjoining light source parallel connections can beconnected to anodes of the LEDs 701 contained in the downstream one.

The patterned conductor 500 a of FIG. 70 has a side frame 524 widthwisespaced from the second trunk path 512 and extending in the longitudinaldirection where the side frame 524 is formed with a plurality of pilotholes 526 for engaging with pilot pins of a press machine to allowprogressive transportation/positioning of the patterned conductor 500 a.The side frame 524 is joined to the second trunk path 512 by a pluralityof widthwise extending joints 525. As described in detail later, bybending the joints 525, the side frame 524 can be used to create a spaceon the underside of the second trunk path 512 for accommodatingconnection wires and the like.

In the light source assembly 700 b of FIG. 71, the first and secondtrunk paths 511, 512 and side frame 524 are cut at appropriate portionssuch that, as in the above embodiment, such that anodes of the LEDs ofthe upstream one of the adjoining light source parallel connections areseparated from cathodes of the LEDs of the downstream one and that theends of each LED 701 are not short-circuited.

FIG. 72 a is a schematic diagram of a light emitting apparatus formed byusing the light source assembly 700 b shown in FIG. 71, and FIG. 72 b isa cross-sectional view taken along the line b-b in FIG. 72 a. As shownin the drawings, in the light source assembly 700 b contained in a lightemitting apparatus 710 of FIG. 72 a, three light source parallelconnections, each of which comprises three parallel connected LEDs 701,are connected in series. Of course the number of LEDs 701 contained ineach light source parallel connection and the number of light sourceparallel connections connected in series can by varied arbitrarily. InFIG. 72 a, the side frame 52 is not shown.

The light emitting apparatus 710 comprises a glass tube 711 foraccommodating the light source assembly 700 b, and a pair of caps 712,713 provided on either side of the glass tube 711 so as to protect thelight source assembly 700 b from dust or the like. The caps 712, 713 areeach provided with a pair of conductive pins 714, 714 and 715, 715 forelectric connection. The pair of conductive pins 714, 714 of one cap 712(the left one in the drawing) are passed through the cap 712 to beconnected to a pair of input terminals of a diode bridge 716 disposedwithin the glass tube 711. Further, the pair of conductive pins 714, 714of the cap 712 are connected to the corresponding pair of conductivepins 715, 715 via associated connecting wires 717, 718. In this way,when another light emitting apparatus 710 a having an identicalstructure is axially joined to the light emitting apparatus 710, thepower supply voltage can be easily transmitted to the another lightemitting apparatus 710 a via the connecting wires 717, 718 and theconductive pins 715, 715. One (a higher voltage side in this embodiment)of a pair of output terminal of the diode bridge 716 is connected to ananode side of the LEDs 701 of the electrically most upstream lightsource parallel connection in the light source assembly 700 b, while theother (a lower voltage side in this embodiment) is connected to acathode side of the electrically most downstream light source parallelconnection via another connecting wire 719.

As shown in the cross-sectional view of FIG. 72 b, by bending the joints525 at positions indicated by arrows A and B in FIG. 71, the side frame524 can be placed to face the second trunk path 512 so that a space isformed between the side frame 524 and the second trunk path 512 foraccommodating the connecting wires 717, 718, 719. This can hold theconnecting wires 717, 718, 719 in position within the glass tube 711.

FIG. 73 is a partial plan view showing another way of secondaryprocessing of the patterned conductor 500 shown in FIG. 56 for forming alight source assembly having a plurality of light sources spatiallyarranged in a line and electrically connected in a matrix pattern asshown in FIG. 65. In FIG. 73, parts similar to those of FIG. 56 aredenoted with same reference numerals and detailed description thereof isomitted. Also, parts to be cut off are shown by hatching. FIG. 74 is apartial plan view showing a light source assembly achieved by using aconnective conductor structure made from the patterned conductor appliedwith the secondary processing shown in FIG. 73. In FIG. 74, the LEDs 701are shown schematically so that the orientations thereof are indicated.

As shown in FIGS. 73 and 74, in this embodiment, the bridge portions521A are all cut off so that the LEDs 701 are connected in parallelbetween the first trunk path 511 and the second trunk path 512. Further,in a similar fashion as in the above embodiment, the first and secondtrunk paths 511, 512 are cut at an intermediate position betweenadjoining light source parallel connections.

In the embodiment of FIG. 73, the branch paths 513, 514 are left uncut,and the branch paths 513, 514 are bent at positions indicated by arrowsC, D so that the principal surfaces of the first and second trunk paths511, 512 are substantially perpendicular to the principal surface of theinterconnection path 510. Further, the first and second trunk paths 511,512 are bent at positions indicated by arrows A, B toward the center sothat free end portions 511A, 512A formed by the cutting of first andsecond trunk paths 511, 512 are brought into contact with each other.The mutually contacting free end portions 511A, 512A are welded, forexample, to form a conductive path (FIG. 74). As seen in FIG. 74, whenthe LEDs 701 as light sources are attached to corresponding light sourceattachment portions 515 such that the LEDs 701 are all disposed in thesame direction, the conductive path can connect cathodes of the LEDs 701contained in an electrically upstream one (left one in the drawing) ofadjoining light source parallel connections are connected to anodes ofthe LEDs 701 contained in a downstream one (right one in the drawing),to whereby connect the light source parallel connections in series.Further, by cutting the first and second trunk paths 511, 512 atappropriate positions, anodes of the LEDs 701 contained in theelectrically upstream one of the adjoining light source parallelconnections are separated from cathodes of the LEDs 701 contained in thedownstream one and the ends of each LED 701 are prevented fromshort-circuiting. It should be noted that in the embodiment of FIGS. 73and 74, all of the branch paths 513, 514 are left uncut, although it maybe possible to cut off some or all of the branch paths 513, 514 andinstead use resistors having lead wires.

FIG. 75 is a schematic partial plan view showing a light source assemblyformed by using the patterned conductor 610 suitable for arranging thelight sources in two lines as shown in FIG. 63 a such that the lightsources are connected in a matrix pattern. In this drawing, partssimilar to those of FIG. 63 a are denoted with same reference numeralsand detailed description thereof is omitted, and the LEDs are shown bytheir symbols so that the orientations thereof can be indicated. In FIG.75, the patterned conductor 610 is shown in a state after parts thereofhave been cut off as required (i.e., converted into a connectiveconductor structure). LEDs 721 are each connected between the firsttrunk path 611 and the second trunk path 612 or between the second trunkpath 612 and the third trunk path 613 via associated branch paths 616,626 and resistors 722. In each of the two lines of LEDs 721, a pluralityof light source parallel connections, each of which comprises threeparallel connected LEDs 721, are formed such that the orientations ofLEDs 721 contained in adjoining parallel connections are opposite toeach other, as shown by the symbols in the drawing. Further, parts ofthe first to third trunk paths 611-613 are cut off (reference numerals723, 724, 725). In this way, each line of LEDs 721 constitutes a matrixcircuit, and upon application of voltage with the polarity indicated bysymbols, electric current flows generally from the left to right of thedrawing.

FIG. 76 is a schematic view showing a preferred embodiment of a surfacelight emitting apparatus achieved by using a plurality of light sourceassemblies formed according to the present invention. In thisembodiment, a red light source assembly 731 comprising a plurality ofred LEDs (R), a green light source assembly 732 comprising a pluralityof green LEDs (G), and a blue light source assembly 733 comprising aplurality of blue LEDs (B) are used to form a surface light emittingapparatus 730 having a circular light emitting surface. As shown in thedrawing, the three light source assemblies 731, 732, 733 are arranged toform a spiral extending toward the center from their respective startingpoints RS, GS, BS which are circumferentially spaced substantiallyevenly from each other in a periphery of the light emitting surface.This can allow the light of each color to be emitted with the samebrightness and in a substantially circular shape. FIG. 77 shows anembodiment of a square surface light emitting apparatus 730 a formed ina similar manner. Thus, the shape of the surface light emittingapparatus formed can be arbitrarily selected. Further, although in theabove embodiment one light source assembly is used for each color, itmay be possible to use two light source assemblies for each color, forexample, so that the light source assemblies are arranged to formspirals from total of six starting points. The number of colors used maynot be limited to three, and may be two or more than three. Of course,it is also possible to use light sources of a same color in all of thelight source assemblies.

FIG. 78 is a schematic view showing another embodiment of a surfacelight emitting apparatus using a plurality of light source assembliesformed in accordance with the present invention. As shown, in thissurface light emitting apparatus 740, a plurality of red, blue, andgreen light source assemblies are arranged to form concentric circles.It will be understood that as in the above embodiment, such anarrangement also may not be limited to the circular shape.

FIG. 79 is a schematic view showing an example of use of a light sourceassembly (such as the light source assembly 101″ shown in FIG. 36)according to the present invention. In this drawing, the details of theconnective conductor structure 104 are not shown. Since the light sourceassemblies according to the present invention may assume flexibility,they can be twisted when in use as shown in the drawing. This can allowthe light sources 102 to be arranged in a helix to thereby lighten thespace around the light source assembly substantially evenly.

LEDs have considerably longer lifetime compared with incandescent lampsor the like, and therefore, have been recently used as light sources forautomobile lamps such as stop lamps, tail lamp, or turn signal lamps,which require high reliability. When placed in corners of a vehiclebody, for example, such an automobile lamp is required to have threedimensional configuration fitted to the overall design of the vehiclebody, and the LEDs as light sources are accordingly required to bearranged in a three dimensional pattern.

Such an automobile lamp comprising LEDs arranged in a three dimensionalpattern is disclosed in Japanese Patent Application Laid-Open No.11-121807, for instance. The automobile lamp disclosed in this laid-openpublication has a light emitting unit comprising plurality of LEDs, abase having a plurality of steps, and holders fitted in the plurality ofsteps and holding respective LEDs, and the light emitting unit isaccommodated in a lamp chamber defined by a lens and a lamp body.Electric codes are sandwiched between the LEDs and holders toelectrically connect the LEDs. Further, in order to strip off covers ofthe electric codes and expose core wires thereof when the LEDs areattached to the holders, the leads of each LED are formed with a slithaving a width substantially corresponding to a diameter of the corewire. Also, each holder is formed with electric code insertion groovesfor provisionally holding the electric codes before attachment of theLED thereto.

In such an automobile lamp, the light emitting unit, which is a primaryelement of the lamp, can be formed by first attaching the holders to thebase, and then inserting the electrical codes into the insertion groovesof the holders, and thereafter fitting the LEDs in the holders tosandwich the electrical codes between the LEDs and holders.Alternatively, by exploiting the feature that the holders are separatefrom the base, it may be possible to first attach the electrical codesand LEDs to the holders to form a light source assembly, and then,attach the holders to the base to form the light emitting unit.

In such an automobile lamp, however, since the holders are separate fromthe base, the number of component parts is increased, which can lead toincrease in the cost for managing the component parts as well as themanufacturing cost. If the holders are made unitary to the base, it willcomplicate the shape of the base, and can increase the cost of moldingdies for forming such a base. Further, in either of the assemblyprocesses described above, it is necessary to insert the electric codesinto the insertion grooves of individual holders, and thus automationthereof is quite difficult. Also, the use of LEDs having leads of aspecial shape hinders use of LEDs available on market, which also can bea factor for increasing the manufacturing cost.

FIG. 80 is a perspective view of an embodiment of a light emittingapparatus for use in automobiles using light source assemblies accordingto the present invention to solve the above problems. This lightemitting apparatus 800 comprises a plurality (nine in this embodiment)of LEDs 802 as light sources, and a base (holder) 830 having a pluralityof steps for arranging the LEDs 802 in a three dimensional pattern. Likethe conventional embodiment, the light emitting apparatus 800 can beaccommodated in a lamp chamber defined by a housing (not shown)constituting a part of the vehicle body and a lens (not shown) attachedto the housing. In this embodiment, each LED 802 has a plate-shapedanode terminal 803 a and cathode terminal 803 b.

In this embodiment, three LEDs 802 are parallel connected to form alight source assembly 801, and three such light source assemblies 801are connected in series by jumper members 815 to thereby form aso-called matrix circuit (or parallel-serial connection circuit). Thoughin this embodiment adjoining light source assemblies 801 are mutuallyconnected at their end by the jumper member 815, it may be possible touse more than one jumper member 815 at a plurality of positions in orderto decrease electric resistance, improve heat conductivity and so on,and the number of jumper members 815 can be arbitrarily determined. Alsoin this embodiment, the jumper member 815 consists of a plate-shapedconductor bent at appropriate portions, but it may consist of a coveredconductive wire, etc.

FIG. 81 is a perspective view showing the light source assembly 801before being bent to comply with the shape of the base 830, and FIG. 82is an end view thereof. As shown, the light source assembly 801comprises a connective conductor structure 804 for electricallyconnecting a plurality (three in this embodiment) of LEDs 802. Theconnective conductor structure 804 comprises a pair of conductors (trunkpaths) 811, 812 extending in parallel in the longitudinal direction, andthe anode terminal 803 a and cathode terminal 803 b of each LED 802 arewelded to the associated trunk paths 811, 812 preferably by laserwelding. In other words, in this embodiment, the pair of trunk paths811, 812 include the light source attachment portions (or light sourceterminal connection parts).

In this embodiment, the trunk path 812 to which the cathode terminal 803b of each LED 802 is attached has a larger width than the trunk path 811to which the anode terminal 803 a is attached, and thus conducts heatmore efficiently. Typically, in each LED 802, an LED chip (not shown)encapsulated in an LED package is directly attached on the plate-shapedcathode terminal 803 b and connected to the anode terminal 803 a via alead wire or the like, and as a result, a large part of the heatgenerated from the LED chip is dissipated to outside through the cathodeterminal 803 b. Therefore, the larger width of the trunk path 812 towhich the cathode terminal 803 b is connected can achieve more efficientheat dissipation from the LEDs 802. The smaller width of the trunk path811 to which the anode terminal 803 a is connected and thus which makeslittle contribution to the heat dissipation can achieve a smaller widthof the resulting light source assembly 801.

In a similar manner as in the above embodiments, the light sourceassembly 801 can be formed by attaching the LEDs 802 at appropriateportions of a tape-shaped patterned conductor having a prescribedpattern, and thereafter cutting off parts of the patterned conductor asrequired to make a connective conductor structure 804 for parallelconnecting the LEDs 802. FIG. 83 is a partial plan view of an embodimentof a patterned conductor suitable for forming the light source assemblycomprising the parallel connected LEDs 802.

As shown, this patterned conductor 820 is of a flat tape shape, andcomprises a pair of longitudinally extending conductors (trunk paths)811, 812 and a plurality of branch paths widthwise connecting the trunkpaths 811, 812. As described above, the trunk path 812 to which thecathode terminal 803 b of the LED 802 is attached has a larger widththan the trunk path 811 to which the anode terminal 803 a is attached.Each trunk path 811, 812 is formed with a plurality of pilot holes 818arranged in the longitudinal direction at a predetermined interval sothat the holes 818 can be used in transportation/positioning of thepatterned conductor in a progressive press machine (not shown).

The light source assembly 801 having an arbitrary number of LEDs 802connected in parallel can be formed by attaching the LEDs 802 betweenthe pair of trunk paths 811, 812 of the patterned conductor 820 by laserwelding, for example, and cutting the branch paths 813 connecting thetrunk paths 811, 812, followed by severing the patterned conductor 820so as to be an appropriate length. Because the pair of trunk paths 811,812 are mechanically joined by the branch paths before the attachment ofLEDs 802, handling of the patterned conductor 820 is facilitated, andthis can allow the processes such as attaching the LEDs 802 to thepatterned conductor 820, cutting off of the branch paths 813, andsevering of the trunk paths 811, 812 to be automated in a singlemanufacturing line comprising a progressive press machine and the liketo improve production efficiency. Further, the LEDs 802 are attached tothe patterned conductor 820 by laser welding or the like without usingspecial holders, and this can reduce the number of component parts andthe cost for managing the component parts.

By bending thus-formed light source assemblies 801 as shown in FIG. 81at appropriate portions and attaching them to the base 830, the lightemitting apparatus 800 for automobiles as shown in FIG. 80 can beobtained. The attachment of the light source assemblies 801 to the base830 can be achieved by forming bosses (not shown) at prescribed portionsof the base 830, and fitting the pilot holes 818 of the trunk paths 811,812 of the light source assemblies 801 over the bosses, or by usingadhesive.

It is preferable that each LED 802 is placed at an appropriate positionon the base 830 when the light source assembly 801 is attached to thebase 830. However, if the processing accuracy in the bending of thelight source assembly 801 is low, for example, the LEDs 802 may bedisplaced from the appropriate positions. In such a case, it will bedesirable if the positions of the LEDs 802 can be adjusted to theappropriate positions. Further, though in the above embodiment the LEDs802 in each light source assembly 803 are arranged in a line, there maybe a case where it is desired that the direction of arrangement of theLEDs are offset or curved. FIG. 84 a is a partial plan view showinganother embodiment of a patterned conductor for allowing such adjustmentof LED positions, and FIG. 84 b is a view similar to FIG. 84 a and showsthe parts to be cut off in the useable state by hatching. In thesedrawings, parts similar to those of FIG. 83 are denoted with samereference numerals and detailed description thereof is omitted.

In the patterned conductor 820′ shown in FIG. 84 a, an expandableportion 821 is formed at a prescribed longitudinal position of each ofthe pair of trunk paths 811, 812 such that the expandable portions 821functions to allow adjustment of LED positions. Preferably, theexpandable portions 821 are formed between adjoining LED attachmentpositions. It should be noted that though the pair of trunk paths 811,812 have a same width in FIG. 84 a, they may have different widths as inthe embodiment of FIG. 83.

In the embodiment of FIGS. 84 a and 84 b, each expandable portion 821comprises a pair of substantially U-shaped narrow connection paths 822formed in either trunk paths 811, 812 where a pair of opposing straightparts of each U-shaped connection path 822 extend substantially in awidthwise direction of the trunk paths 811, 812, and a curved bottompart of the same is disposed close to the center axis of the patternedconductor 820′. The expandable portion 821 further compriseslongitudinally extending bridge portions 823 at either lateral edgeportion of the trunk paths 811, 812 for connecting the ends ofrespective U-shaped connection paths 822 to usually prevent deformationof the expandable portion 821. In other words, the bridge portions 823serve as a deformation prohibiting portion. When in use, deformation ofdesired expandable portions 821 is allowed by cutting off the bridgeportions 823 as shown by hatching in FIG. 84 b. Thus, by using thebridge portions 823, it is possible to selectively allow deformation ofthe expandable portions 821 to make the position of associated LEDsadjustable only at places where such adjustment is necessary, and thusprevent unnecessary decrease in the overall mechanical strength of theresulting light source assembly. Further, in a state before cutting offthe bridge portions 822, the patterned conductor 820′ or the lightsource assembly formed by using the same has a relatively high rigidityand thus the handling thereof is easy. Such extendable portions 821 andbridge portions 823 can be formed easily and at low cost by means ofblanking in the press working process.

FIGS. 85 a and 85 b are partial plan view showing exemplary deformedstates of a light source assembly 801′ formed by using the patternedconductor 802′ shown in FIG. 84 a. In FIG. 85 a, longitudinallyadjoining two expandable portions 821 are deformed such that thedirection of arrangement of the LEDs 802 (or a longitudinal axis of thelight source assembly 801′) is bent in a plane parallel to the principalsurface of the patterned conductor 820′ (or connective conductorstructure 804), and as a result, the direction of arrangement of theLEDs 802 is displaced widthwise (or laterally) between the right end andleft end of the drawing. In FIG. 85 b, the expandable portions 821 aredeformed to increase the distance between adjoining LEDs 802 in thelongitudinal direction of the light source assembly 801′. Thus, in thelight source assembly 801′ using the patterned conductor 820′ having theexpandable portions 821, not only the positions of LEDs 802 can beadjustable to ensure that the LEDs 802 can be placed at appropriatepositions on the base, but also various LED arrangements are possible,significantly improving the freedom of design of automobile lamps.Further, it may be possible to use a same light source assembly 801′ fordifferent bases if the difference is such a degree that can be absorbedby the deformation of the expandable portions 821 of the light sourceassembly 801′.

FIG. 86 a is a partial plan view showing yet another embodiment of apatterned conductor having an expandable portion, and FIG. 86 b is apartial plan view showing an exemplary deformed state of a light sourceassembly using the patterned conductor. In these drawings, parts similarto those of FIGS. 84 a-85 b are denoted with same reference numerals anddetailed description thereof is omitted. In FIG. 86 a, parts to be cutoff in the used state are indicated by hatching. As shown in FIG. 86 a,in this patterned conductor 820 a, each expandable portion 821 acomprises a pair of substantially S-shaped narrow connection paths 822 aextending in the widthwise direction of the corresponding trunk paths811, 812. As in the above embodiment, in this patterned conductor 820 aalso, bridge portions 823 a serving as a deformation prohibiting portionfor selectively allowing deformation of the expandable portions 821 aare provided at widthwise outer edge portions of respective trunk paths811, 812 at positions corresponding to the expandable portions 821 a.The expandable portions 821 a and bridge portions (deformationprohibiting portions) 823 a can be also preferably formed by blanking.

As shown in FIG. 86 b, in a light source assembly 801 a that uses thepatterned conductor 820 a shown in FIG. 86 a also, deformation of theexpandable portions 821 a can allow adjustment of the LED positionslaterally or longitudinally in a plane parallel to the principal surface(the surface to which the LEDs are mounted) of the patterned conductor820 a.

FIG. 87 a is a partial plan view showing still another embodiment of apatterned conductor having an expandable portion, and FIG. 87 b is afront view of the patterned conductor of FIG. 87 a. Further, FIG. 87 cis a partial plan view showing an exemplary deformed state of a lightsource assembly using the patterned conductor. In these drawings, partssimilar to those shown in FIGS. 84 a-85 b are denoted with samereference numerals and detailed description thereof is omitted. As shownin the drawings, in this patterned conductor 820 b, expandable portions821 b is of bellows-like or corrugated shape, and have a plurality ofcreases formed by folding the trunk paths 811, 812 along a plurality ofbending lines extending in the widthwise direction of the patternedconductor 820 b. Such expandable portions 821 b can be easily formed bypress working. In a light source assembly 801 b that uses the patternedconductor 820 b also, deformation of the expandable portions 821 b canallow adjustment or alteration of the positions of LEDs 802 such asbending the direction of arrangement of the LEDs 802 in a plane parallelto the principal surface of the patterned conductor 820 b as shown inFIG. 87 c. Further, though not shown, it is also possible to deform theexpandable portions to adjust the distance between adjoining LEDs 802.

FIG. 88 a is a partial plan view of yet another embodiment of apatterned conductor having an expandable portion, FIG. 88 b is a frontview of the patterned conductor of FIG. 88 a, and FIG. 88 c is a partialplan view showing an exemplary deformed state of a light source assemblyusing the patterned conductor. In these drawings, parts similar to thoseshown in FIGS. 84 a-85 b are denoted with same reference numerals anddetailed description thereof is omitted. In this patterned conductor 820c, expandable portions 821 c consist of curved portions raised in adirection of thickness of the patterned conductor 820 c. Each curvedportion 821 c has a narrow longitudinally middle part so as tofacilitate deformation. It can be said that this embodiment correspondsto a particular case of the embodiment shown in FIG. 87 a-87 c in whichthe number of creases is one. In a light source assembly 801 c that usesthe patterned conductor 820 c also, deformation of the expandableportions 821 c can allow adjustment or alteration of the positions ofLEDs 802 such as bending the direction of arrangement of the LEDs 802 ina plane parallel to the principal surface of the patterned conductor asshown in FIG. 87 c.

FIG. 89 a is a partial plan view showing another embodiment of apatterned conductor suitable for forming a light source assemblycomprising a plurality of parallel-connected light sources according tothe present invention. As shown, this patterned conductor 850 also has asubstantially flat tape-like shape, and comprises a pair oflongitudinally extending and mutually spaced apart conductors (trunkpaths) 851, 852 and a plurality of branch paths 853 joining the trunkpaths 851, 852. In this embodiment, it is intended that the upper trunkpath 851 in the drawing is attached with an anode terminal of LEDs whilethe lower trunk path 852 is attached with a cathode terminal of LEDs.Thus, for the same reasons as described with respect to the embodimentof FIG. 81, the trunk path 852 has a larger area than the trunk path851. Each trunk path 851, 852 is formed with a plurality of pilot holes858 arranged in the longitudinal direction at a predetermined intervalso that the holes 858 can be used in transportation/positioning of thepatterned conductor in a progressive press machine (not shown).

In this patterned conductor 850, a gap 855 between the pair of trunkpaths 851, 852 is not straight but is bent in a rectangular wave. Inother words, mutually facing sides of the trunk paths 851, 852 areformed with protrusions and recesses alternating in the longitudinaldirection such that the protrusions formed in one of the trunk paths851, 852 are longitudinally aligned with the recesses formed in theother of the trunk paths 851, 852 whereby the former projects into thelatter. Owing to such a structure, it is possible to displace the pairof trunk paths 851, 852 from one another to adjust the distancetherebetween not only in the widthwise direction but also in thelongitudinal direction. The above described patterned conductor 850 canbe formed easily by press working a flat conductor.

FIG. 89 b is a plan view of a light source assembly formed by using thepatterned conductor 850 of FIG. 89 a. In this drawing, the LEDs areshown schematically to indicate the orientation thereof. This lightsource assembly 860 can be formed by attaching LEDs 861 to the patternedconductor 850 by laser welding, for example, and then adjusting thedistance between the pair of trunk paths 851, 852 in the lateral andlongitudinal directions as well as cutting off the branch paths 853. Asshown, in this embodiment, the gap between the pair of trunk paths 851,852 of the patterned conductor 850 is not straight, and has a partextending in the widthwise direction, and therefore, it is possible tosignificantly vary the positions of the LEDs 861 not only in thelongitudinal direction but also in the lateral direction (widthwisedirection). This allows light source assemblies 860 having various LEDarrangement patterns to be formed by using the same patterned conductor850. Thus, it is possible to cope with such a situation that the lightsource assemblies 860 are used in forming automobile lamps in whichdifferent LED arrangement patterns are demanded for different vehicles.This can lead to parts sharing and bring about significant economicbenefits.

As described above, according to the present invention, various lightsource assemblies having different light source connection patterns canbe formed in a same manufacturing line from a patterned conductor formedwith a commonly usable prescribed circuit pattern, and therefore, it ispossible to improve the production efficiency and significantlycontribute to reducing the manufacturing cost. Further, because noprinted circuit board is used and thus there is no solder used forconnection with the printed circuit board, it is possible to eliminateconcern about environmental problems as well as possibility that theLEDs may be damaged by heat generated along with the use of solder.

Although the present invention has been described in terms of preferredembodiments thereof, the embodiments are for illustrative purposes onlyand the present invention should not be limited by the embodiments. Itis obvious to a person having ordinary skill in the art that variousalterations and modifications are possible without departing from thescope of the present invention which is set forth in the appendedclaims. For instance, though in the embodiments of FIG. 16 and FIG. 29the joint members 115, 116 are formed by insert molding, it may bepossible to separately form upper and lower parts of the joint member,and in a state that the patterned conductor 120, 170 are interposedtherebetween, bond the upper and lower parts by adhesive or the like toform the joint member. Also, though the LEDs are used as light sourcesin the embodiments, the present invention can be applied to other lightsources (such as cap-less incandescent lamps).

1. A light source assembly comprising: a plurality of electricallyconnected light sources; and a connective conductor structure extendingin a direction of arrangement of the light sources to join the lightsources, wherein the connective conductor structure is formed by cuttingoff parts of a substantially plate-like patterned conductor as required,the patterned conductor being provided with a prescribed pattern,wherein each of the light sources has a pair of terminals; wherein thepatterned conductor is of a longitudinal tape-like shape, and comprises:a plurality of light source attachment portions arranged in alongitudinal direction for electrical connection with the light sources;an interconnection path for connecting the light source attachmentportions in the longitudinal direction; a pair of trunk paths disposedon either side of the patterned conductor so as to interpose theinterconnection patch and the light source attachment portionstherebetween and extending in the longitudinal direction; and aplurality of branch paths widthwise connecting the trunk paths to theinterconnection path; each of the light source attachment portions has apair of terminal connection parts corresponding to the pair of terminalsof the light sources, and the interconnection patch comprises aplurality of connection paths each connecting the terminal connectionparts contained in adjoining light source attachment portions such thateach terminal connection part of each light source attachment portion isconnected to one of the terminal connection part of an adjoining lightsource attachment portion by an associated connection path; wherein theconnective conductor structure is formed by cutting off a portion of thebranch paths, interconnection patch or trunk patch of the patternedconductor to select one of series, parallel and series-parallelconnections of the light sources.
 2. A light source assembly accordingto claim 1, wherein a resistor is connected between at least one pair ofadjoining light sources, and the interconnection path is cut at aposition between the pair of adjoining light sources.
 3. A light sourceassembly according to claim 1, further comprising a joint memberextending in a widthwise direction of the connective conductor structureto hold the interconnection path and the trunk path in a unit.
 4. Alight source assembly according to claim 3, wherein the joint member isformed by insert molding.
 5. A light source assembly according to claim3, wherein the trunk path is formed with a widthwise recess orthrough-hole, and the joint member extends through the widthwise recessor through-hole.
 6. A light source assembly according to claim 3,wherein the joint member is formed with a hole at a position alignedwith the interconnection path such that the hole exposes theinterconnection path, thereby allowing a part of the interconnectionpath exposed by the hole to be cut off.
 7. A light source assemblyaccording to claim 3, wherein the joint member comprises one or aplurality of insulating sheets.
 8. A light source assembly according toclaim 1, wherein the branch paths connecting the trunk path to theinterconnection path are bent such that a principal surface of the trunkpath is substantially perpendicular to a principal surface of theinterconnection path.
 9. A light source assembly according to claim 1,wherein the plurality of light sources comprise a chip-type LED, and thelight source assembly comprises a socket for receiving the chip-typeLED, the socket extending in a widthwise direction of the connectiveconductor structure to hold the interconnection path and the trunk pathin a unit.
 10. A light source assembly according to claim 1, wherein atleast one of the light source attachment portions is not attached with alight source.
 11. A light source assembly according to claim 1, whereinthe pair of terminal connection parts of the light source attachmentportions are arranged in the widthwise direction of the patternedconductor.
 12. A light emitting apparatus comprising the light sourceassembly according to claim 1 and a holder for holding the light sourceassembly, wherein the branch paths connecting the trunk paths to theinterconnection path are bent such that a principal surface of eachtrunk path is substantially perpendicular to a principal surface of theinterconnection path, and the trunk paths are inserted intocorresponding holes or recesses provided to the holder to achieveattachment of the light source assembly to the holder.
 13. A lightemitting apparatus comprising the light source assembly according toclaim 1, further comprising: a light transmissive tubular member foraccommodating the light source assembly therein; and a pair of capmembers attached to either end of the tubular member.
 14. A lightemitting apparatus according to claim 13, wherein a conductive pin forconnection with an outside circuit is held in at least one of the pairof cap members, and the trunk path is connected to the conductive pin.15. A light source assembly according to claim 1, wherein parts of thetrunk path are cut off so that the connective conductor structureconnects the light sources in series, and remaining parts of the trunkpath are connected to the light source attachment portions via thebranch paths.
 16. A light source assembly according to claim 7, whereinthe insulating sheet is attached to a light source attachment surface ofthe connective conductor structure.
 17. A light emitting apparatuscomprising the light source assembly according to claim 1 and a holderfor holding the light source assembly, wherein at least one surface ofthe holder is formed with a channel having opposing side walls in whichlongitudinally extending guide grooves are formed corresponding to thepair of trunk paths so that the light source assembly is attached to theholder by sliding the pair of the trunk paths into the guide grooves.18. A light emitting apparatus comprising a plurality of light sourceassemblies according to claim 1, wherein the plurality of light sourceassemblies are arranged in the widthwise direction, and adjoining lightsource assemblies are connected to each other so that the plurality oflight source assemblies are connected in series.
 19. A light sourceassembly according to claim 1, wherein parts of the interconnection pathand branch paths are cut off to form a plurality of light sourceparallel connections each comprising a plurality of light sourcesconnected in parallel between the pair of trunk paths, and further,parts of the trunk paths are cut such that the light source parallelconnections are connected in series.
 20. A light source assemblyaccording to claim 19, wherein each of the light sources consists of anLED, wherein orientations of the LEDs contained in adjoining lightsource parallel connections are opposite to each other so that cathodesof the LEDs contained in an electrically upstream one of the adjoininglight source parallel connections are connected to anodes of the LEDscontained in a downstream one via one of the pair of trunk paths, andwherein the pair of trunk paths are cut such that anodes of the LEDscontained in the upstream one of the adjoining parallel connections areseparated from cathodes of the LEDs contained in the downstream one andthat ends of each LED are not short-circuited.
 21. A light sourceassembly according to claim 19, wherein each of the light sourcesconsists of an LED, wherein portions of the pair of trunk paths areconnected to each other via the branch paths and the light sourceattachment portions such that cathodes of the LEDs contained in anelectrically upstream one of the adjoining light source parallelconnections are connected to anodes of the LEDs contained in adownstream one, and wherein the pair of trunk paths are cut such thatanodes of the LEDs contained in the upstream one of the adjoiningparallel connections are separated from cathodes of the LEDs containedin the downstream one and that ends of each LED are not short-circuited.